You want to be a model, or you want someone to ask you to be a model?
Well, there are certain criteria modeling agencies look for in models that they hire.
#1, height doesn't matter in this career. There's a place in the magazine for every person.
Personality is something that's important too. You need to have confidence and positive energy and walk around showing it. Have your head up high, shoulders square, and don't feel ashamed or too self conscious.
In modeling, there are various different markets, and choosing the one that you are most suitable for will have a major effect on your success. The main markets are for catwalk, plus-size, commercial, and swimsuit/lingerie models.
A model's portfolio is incredibly important, as it includes pictures and past work, and is the first thing casting agents, brands, or designers will look at, in order to determine if they want to work with you.
Of course, when you're just starting out modeling, your portfolio, also known as a book, will be sparse. In time and with success, it will expand. For now, though, ask a friend to take a few snapshots of you to give agencies an idea of your look. Your pictures might not be up to professional standards, but try to use a nice camera and make sure the lighting is flattering.
First of all, do your research and make sure to find reputable agencies that cater to the market you're interested in. Then, check out the agencies' websites to find out how they prefer you to submit your book
Excerpts taken from http://www.collegefashion.net/fashion-tips/models-101-how-to-start-your-modeling-career/