This is taken from a blog I really like (Dead Fleurette - which is now a 
new blog).  But this post, is a reprint from a different article ( Secrets of French Girls by Ellen Wallace).  Though written in 1982 (!) the advise is timeless.  I'm posting here because she changed to a new blog & I don't want to have her blog come down & I lose the post :(
Here is another post of hers that I love:
The Long Way to a Perfect Wardrobe, part 2
Now, the text from Dead Fluerette's blog... 
copied & pasted:
I stumbled across a very inspiring and intriguing article by Ellen  Wallace in Cosmopolitan. French style and aesthetics = timeless. The  article was written in August 1982. I didn't notice the year it was  published until after reading it, because everything is absolutely on  target and relevant. The article is long, but the ten minutes you spend  on reading this piece is completely worth it, I tell you. If you don't  have time, read the quotes and the useful tips that I have highlighted.
Oui…Parisians always manage to look fantastique —  even in “les blue jeans.” Jet with us then to cafe-lined boulevards and  learn about French fashion flair!
The one thing they don’t tell you in travel brochures about Paris is the  first thing every visitor notices: People stare. They stare at you;  they stare at everybody. And everybody stares back.
My first taste of this phenomenon terrified me. I was wearing an  overloaded backpack and a wrinkled black dress, which I had slept in on  the train. My mascara was mostly on my cheeks. I wanted desperately to  be inconspicuous, but there they were, all those terrible suave-looking  Frenchmen I had heard about, staring right at me. I wanted to melt into  the sidewalk!
There was also no way to avoid noticing something else: Those French  girls look better than we do. Of course, the mysterious allure of the  French woman is nothing new. She has been the target of love, lust, and  intrigue in hundreds of books and films. Remember Gigi, that innocent  heartbreaker? And Edith Piaf, the enigmatic, real-life heroine who  stunned the world with her gutsy love songs? Not to mention the  quasi-Parisiennes — protagonists of a dozen American novels who left  home frumpy and meek, only to return from Paris a year later ravishing  and self-assured. After devouring those stories, I could never quite  give up the notion that a few months in France and — voila! — I would be  magically transformed.
Alas, at the end of a year in Paris, I still looked moderately frumpy.  In the interest of self-improvement — or maybe survival — I set out to  determine why those French girls look so special. There must be a  secret, I told myself, and I was going to discover it. The first step  seemed obvious: Observe. So I settled down for the evening in what  struck me as a good spot, the Cafe Select on Boulevard Montparnasse.  Before long, three French women sat down next to me. Thinking I had  found my first victims, I eagerly pulled out my note pad.
Unfortunately, my analysis wasn’t terribly enlightening. 
The women all looked pretty and sophisticated in a carefree, natural way. They  had on clothes my American friends might wear: denim skirts, nice  shirts with pullovers, and low-heeled shoes. There was nothing overtly  French about their features and coloring, yet they looked Parisian to  the core. Why? The only distinctive things I noticed were that two wore  bright narrow belts over their sweaters, something most Americans —  waistline conscious — would hesitate to do, and all three had perfect  hair.
I was puzzled. None of them was doing anything an American friend might  not try, but somehow the total look wasn’t the same. So, a few nights  later, I decided to proceed to step two: Ask the French. This tack  proved more successful, although I could see the Parisiennes were  wondering why I was asking such elementary questions.
Pascale, in her thirties, helps manage a restaurant on one of the large  tourist boats that run up the Seine. She has lived in the Far East and  traveled widely, so I was certain she could explain why French women are  more chic than others.
“Bof!” she declared while sniffing a vat of spaghetti sauce in her  kitchen. (This is one of those untranslatable French words that let you  know you have just said something absurd.) I was startled. “French women  are not chic! Oh, yes, there are some chic women — there are always  some — but most? … bof! In my father’s generation, women always had to  be dressed up and looking their best, but that’s changing. Women now are  working, we don’t have as much time to worry about our appearance.”
Yet, I demanded, isn’t it true that Parisians wearing pants look better  than women elsewhere in pants? Pascale wiped her hands on the large  chef’s apron that covered her oversize khaki shirt jacket and black  cotton pants. I noticed that she had on flat, well-made black shoes.  Simple, neat.
It turned out we had a semantics problem: “Oui, if that’s what you mean by chic. 
Elegance  is different than chic; elegance has to do with money, with leisure  time, with upbringing, and education. The chic woman looks natural, not  dressed up. Chic is not a matter of money. Chic means that, from head to  toe, there is a sense of proportion.” And she suddenly reproportioned her sauce with a splash of white wine.
“
When I see American women dressed up,” Pascale continued, “
I  can see they’ve made an effort. Costumes and clothes have always been  more important in France than in America — perhaps it’s historical  influence of artists here. In order to develop a sense of what looks  natural, which proportions are right, one must make an effort each day —  not just occasionally. Here we are told, from the time we’re small,  what looks right, what doesn’t. Our mothers tell us; magazines tell us;  friends tell us.”
More specifically, what does a French mother tell her daughter? “She  discusses colors. The basics — black, white, navy, burgundy, and beige —  are the foundation of an outfit. Black is especially good because you  can wear whatever you want with it. American women tend to mix too many  colors, which is distracting, not chic. I’ve also noticed that they  often wear trendy shoes, rather than investing in classic, well-made  styles.
“In France, we’re also taught to know our own figures and to  transform faults into assets. I know one large woman who has an equally  generous personality — her wardrobe reflects her personality and size.  Above all, you must be at ease in your clothes; a woman who is plump  usually can’t wear tight things. On the other hand, there aren’t rigid  rules, just guidelines. A woman with large breasts is often told not to  wear raglan sleeves, but if the shirt is cut well, sometimes this sort  of sleeve can flatter her.”
One of the earliest lessons a French girl learns is to invest well in her clothes.
 “Chic is knowing how to buy something that will last,” Pascale told me. 
“My  basics must last for at least five, and often ten or fifteen, years. By  basics, I mean clothes that I can wear from morning through the night.  Maybe in the evening I’ll add a special necklace and bracelet, or a  dressy belt — the accessories make the difference.”
Two other French women, Guillemette and Marie-Laure, took up where  Pascale left off, remembering how they learned to dress. The night we  met, Marie-Laure was wearing white pants, a lacy white blouse,  black-and-white belt, white shoes, white net stockings, and gold  jewelry. Somehow, she had managed to avoid looking overdone.  Guillemette, as always, had made up her eyes and mouth perfectly, but  subtly. Her long hair was neatly pulled to one side and braided.
“When I was little,” said Guillemette, “my mother used to help me set  out my clothes every night before school. She would say, ‘Yes, that  looks good together,’ or ‘No, you can’t wear that color with this one — 
marry your colors well.’ “
Marie-Laure nodded. “The mother’s influence is very important to a  French girl’s developing a sense of style. I remember one time I wanted  to buy a turquoise dress and my mother refused, saying it was a bad  color. 
We are taught to be discreet, subtle in our choice of color.  There is nothing wrong with bright color, but it has to be worn  delicately — it shouldn’t shout at you.”
They agreed with Pascale that French women are less chic than they once  were but attributed this fact to the cost of clothes in France today.  “Italian women are the chic ones now,” said Guillemette, whose in-laws  live in Italy. “Chic is a matter of how you put yourself together, and  here even the smallest pieces of clothing costs so much. A really nice  skirt or jacket by a designer — even prêt a porter — is extremely  expensive. That’s why the young are always running around in jeans,  clogs, and Indian clothes!”
I was beginning to feel confused. True, not every woman on the streets  of Paris looks terrific (some of the worst dyed hair in the world can be  found here), but enough of them do to make the rest of us take notice.  Aren’t French women, in fact, more chic? I checked with Judy Fayard, a  Life magazine assistance editor and former Women’s Wear Daily reporter,  who has been watching the Paris fashion scene for almost ten years.
“In general, they are more chic,” she assured me. “Awareness of style is  all around them because Paris has been the fashion capital for so long.  There is exposure to what designers are doing, and it penetrates down  to the woman in the street faster here than anywhere.
“French women are also much more aware of themselves than your average  American. They take better care of their bodies. It isn’t just a  question of weight. Here, even women of modest means visit the beauty  salon regularly — to have their legs depilated or to tan or have their  nails done. They always have their hair cut well, and I don’t think this  is because they have better haircutters, but because Parisians go more  often. They have the same attitude toward their bodies and clothes as  they have toward food. They are willing to spend their money on it.”
Judy feels that there are three basic differences between French and  American women. “French women are more self-confident in general, and  this carries over into dressing. They are willing to experiment — say,  to roll up the sleeves of a silk shirt and wear it with jeans or stick a  gold belt on jeans. I can’t think of any American woman who would do  that until she had seen it in a magazine.
“Second, the French are basically conservative but without the sense  of practicality that Americans have. Most American women are too  practical to buy a wardrobe of different stockings to accessorize their  basic clothes.”
The greatest difference, she noted, is that looking nice has become a  habit for French women. “At 9:00 A.M. at the corner market, I’m the  only one with my hair in a ponytail and no makeup. American women either  get dressed up — and when they do, you know they’re dressed up — or  they simply ‘throw something on.’ There’s no such phrase in French!  French women simply don’t go around looking sloppy.”
Judy also pointed out that one can still get better-cut clothes in Paris  — even non-designer garments mimic the flattering lines of more  expensive wear. French women still try, she added, to buy at least one  nice — undoubtedly expensive — dress or suit and use accessories (a  cheap belt, scarf, or pin) to alter it during the course of frequent  wearings.
Although the French buy outfits just as American women do, they tend to  skillfully mix the separate pieces and not wear the matched ensemble as  often. 
“They seem to have a practiced eye for proportion — when the hem goes up, the shoe goes down,” Judy said. “It must be training. If you see good stuff around you often enough, you start to imitate it.”
Looking around might have helped those fictional heroines who went home  chic, but they also must have had plenty of francs. This season, a  decent pair of shoes in Paris costs at least $60; really nice pairs run  from $80 to $150.
A British woman who has made Paris home for four years explained that  the price of clothes affects how you wear them. “You can buy cheap  French clothes, but they give out right away,” Evelyn said. “So you have  no real choice but to spend more initially, knowing it will cost less  in the long run. 
French women never keep their good clothes in the  closet. They don’t wear clothes they don’t like in order to ‘save’ their  favorite things for special occasions — they simply can’t afford to!
“Two years ago I bought a pair of St. Laurent pants on sale,” Evelyn  continued. “Even then, they cost a bundle but I knew I could wear them  for years. This winter I had them altered so the legs would be more in  style; otherwise, they would hang in the closet. That’s what you have to  do with your clothes here — make them last.” Evelyn pointed out  that within a block of her apartment, there are three alteration shops,  doing lively business. Nearby shoe-repair stores are also thriving.  Women who buy expensive shoes often take them to the shop immediately to  have protective layers put on the soles, so the leather will last  longer.
Maite Turgonet, a Parisian journalist who covers the fashion world,  concurred that French women are less chic than they once were. By this  time, however, I was beginning to understand that what we consider chic  is something the French take for granted as a basic starting point. For  them, chic is something beyond that! So, for starters, I asked her what a  Parisian would consider the key to simply looking nice.
“French women avoid clothes that are shocking,” she said. 
“We  have a strong sense of not wanting to appear ridiculous. Even in the  craziest French fashions, there is always a classical base; clothes must  be cut well."
“Here a woman tries to be subtle,” she continued. “In New York, women seem to need to prove they are aware of fashion. 
The  really fundamental rule is always be neat. You should be clean, your  clothes ironed, your shoes polished. Then you must know and accept  yourself; don’t try to hide your faults — that will only make you  uncomfortable because you will be fighting what you are. American women often seem to be striving for some norm. 
If you’re short, there is no point in wearing high heels just to make yourself look taller.”
And if that’s the key to looking nice, then what elusive quality constitutes chic? What makes a classy woman stand out?
“Personality. Self-confidence. 
A French woman dresses for herself,  tries above all to please herself in the way she looks — because she  must, if she’s going to please others.
Pascale had made a similar comment. 
“Chic is not a question of beauty  or shape or age. It’s developing a self-identity, which you reflect in  the way you dress. The sensuality of such a woman is subtle.”
Maite added that 
French women do not dress for men. “French women  don’t dress to be sexy. Of course we do dress to seduce — that’s  different from trying to ‘catch’ a man by wearing flamboyant clothes.  The basic attitude is different. A French woman never feels she’s  offering herself. There’s never a sense of surrender, but an attitude of  ‘I belong to me’.”
A few nights later, I brought the subject up again, at a dinner party. I  was surprised to note that the men were as interested as the women.  Since roles are more vaguely defined in France, men are free to talk  finance and fashion.
“French women never try to look younger than their age,” said a businessman named Patrick.
  “A woman of seventy can be more interesting than one of twenty. And  they never try to fill a stereotype; each woman tries to find her own  style.”
“Here, there’s an emphasis on imagination and creativity,” added Claude,  a banker. “In the United States, you can buy anything in any color, but  in France the market is smaller, so designers have to decide that this  year they’ll sell red — they can’t afford to manufacture small  quantities in lots of different colors Given that, French people must  use imagination just to differentiate themselves.”
Odile, a translator, agreed. “a French woman tries to wear something  that brings out her individual personality. If you see an American woman  who is considered chic, she’s usually sun tanned, has long legs, is  blond, and sportif — but looks just like everybody else who is this sort  of chic!”
Another guest, Isabelle, had just come back from a vacation in Palm Beach. 
“In  Florida everyone wears shorts and T-shirts during the day, then at  night they dress up to seduce. In France, seduction is an all-day  affair, part of your look, not just your clothes. It isn’t something you turn on and off.”
I asked Isabelle if she had noticed that American women look at  themselves more self-consciously. She thought a minute. “Actually,” she  said slowly, “they don’t seem to examine themselves critically very  often.” The others, most of whom have visited the States at least once,  found that American women seemed a bit puritanical and shy about their  bodies. A French woman, for example, is more relaxed about discussing or  touching her breasts in public, if, say, conversing with a friend about  the cut of a new bathing suit.
More to the point, French women frequently stop to check their  appearance in mirrors — and without the self-consciousness that we have.  This might be partly because there are more mirrors in Paris (in cafes,  in the subway, on storefronts). These self-assessments don’t seem to  stem from vanity, however, but from an honest desire to avoid  sloppiness.
My conversations with chic Parisian weren’t completely theoretical,  though. I did glean a few specific tips, just the sort of advice that  made all the difference to those frumpy, fictional heroines:
~ If you need a basic addition to your wardrobe — such as a winter  coat or suit — spend as much as you can afford on it and do without  something else. Consider the new item an investment, just as you would a  new car — you’ll probably spend as much time in it. If it’s still  wearable in five years, you will have saved money in the long run.
~ Basic, conservative colors are sensible and attractive; but don’t  forget to add accessories. Brighten up a navy, tailored skirt and white  blouse by draping a pretty wool plaid scarf around your shoulders.
~ Don’t be afraid of a touch of frivolity — little pop elephant pins,  plastic banana-shaped earrings, or hats (but no feathers or loud  ribbons, please!) Wear very few other accessories with these in order  not to clutter.
~ The focal point of an outfit need not be one of the large pieces.  If you’ve splurged on a gorgeous pair of shoes that flatter your legs,  draw attention to your feet by downplaying the rest of your clothes. You  have a nice waistline and a pretty gold belt? Wear it with black pants  and a black sweater — forget the old rule that gold and silver are just  for dressing up.
~ When window shopping, try to envision clothing as more than what it  was designed to be. One Parisian visiting New York for the first time  saw a pair of boys’ black-and-white, ankle-high basketball shoes, and  she decided that they would make great casual boots. She wears dark  cotton pants tucked into them — très chic!
~ If you’re a few pounds overweight, don’t try to hide under loose,  shapeless clothes. Fitted pants and dresses that are well cut will be  more flattering and make excess weight less noticeable.
~ Avoid pastels, except as accessories. They flatter no one.
I’m pleased to report these practical tips helped me considerably — in  fact, I might even approximate one of those rags-to-ravishing heroines  on my next trip home! I returned to the Cafe Select with another  formerly frumpy American. We spent an hour just watching women walk by.  It was pleasant because too many Parisian women look great, though they  may not think they’re as chic as they once were; nevertheless, they are  often well dressed, wearing tastefully coordinated colors and flattering  makeup and hair styles. Even more striking, most of them have an aura  of self-assurance, which we Americans rarely possess. For whatever  reason, we often seem dissatisfied with ourselves. We keep looking for  that elusive outfit that will somehow change everything. French women do  it the other way — first, they learn to appreciate their looks, then  they decorate the package. When we left the cafe, we passed an  art-supply shop with a mirror in the window. An attractive woman of  about forty-five paused before it to check her lipstick. Just as we  reached her, a man passed and whispered, “You’re beautiful!” She laughed  pleasantly and walked off. I got the feeling that — without conceit —  she knew exactly what he meant.
(Article via Eurochic.)