WALK THE LINE

A model, especially to designers and photographers has to be like ...a walking line drawing. A line drawing are those sketches designers draw to visualize a new design. To them the girl is this long elegant line that makes their dresses and coats and pants look wonderful (see Stella Tennant). This is one reason why models are so unnaturally thin... to achieve this impossibly long, idealized line. The Industry standard for  womens clothing samples runs at a size 6 and with some designers even to size 4.  This is why a smaller but very proportionate girls like Kate Moss, Kiara and Jamie Rishar will be allowed into the modeling ranks. They give a "long", lean appearance, even though they're not at all tall.  An outfit, if a girl is 5 '5" and 95 lbs, can be downsized to fit her, but if a woman dares to go beyond a size 6, the industry will not adjust.
This is why Cindy Crawford with the healthy body of a fully fledged woman is hardly ever seen on the runway or in editorials anymore. (Not that her income is suffering but this is because Cindy is now beyond runways - you the beginner, are not).
 

THE PERFECT EDITION OF YOU

Here's a cautionary tale to turn your young hearts cold: A brand new beauty is selected by John Galliano to open his first Givenchy show. I mean he loves this girl to death, showering her with "fabulous darlings"... the whole cliché.  She walks out in her first outfit shaking with fear, wobbling in her heels  and glancing around like a frightened deer. That was it. She was finished. She hasn't been heard of since.
Poise, apart from show stopping beauty is the most important element to becoming a supermodel. Practice smiling deeply  into people's eyes as you shake their hands. Everyone loves a sweetheart. They'll be time enough in the future for you to evolve into a psychotic diva.

Everyone prefers working with a likable individual as opposed to someone rude or awkward. Being charming is a virtue but don't kiss ass as noted casting director Neil Gabler,  "There's nothing more unattractive than a desperate model. When a cool kid comes in with a pleasant, professional attitude and a kind of take-or-leave it air about them that sticks in my mind more than somebody who's doing handstands to impress me." The opposite situation is not ideal either, this business will not humor a model who breaks out into a cold sweat everytime he goes on camera and if you're uptight about undressing in front of strangers, this is the worst line of work you can imagine.

Having established that you're a striking boy or girl with killer bone structure and perfect skin, having realized that you are tremendously photogenic, and wear clothes with great style, then you truly have the basic ingredients for success. Ask yourself this: "In addition to my physical beauty, am I a pleasant and confident person who walks around with poise and presence?"  If you can truthfully answer yes, then you're set to move on to the next level.
  

So Ya Wanna Be A Supermodel - Part 2
Getting Started: The 'Low Down' On Modeling Agencies