As a model, the best way to increase your chances for success is to evaluate yourself as a model properly and target that specific part of the market that best fits your features.
The two most popular and obvious types of models (and market sections) are "fashion" and "glamour" models (markets). Both have very well-defined specifications and requirements, that, unlike most models want to believe, are completely different from each other. And also the way those two markets operate is completely different - real fashion clients only work through agencies.
A common mistake most models make is aiming at the "high-fashion" market, without meeting the criteria or knowing what "high" fashion even means. Even though when you hear "model" you don't think of a Harvard graduate, most of the successful models are extremely smart and well educated. Always research and be realistic! Even though Kate Moss is just 5'7", she should not be your guide-star. The industry rarely makes exceptions. All model markets are very profitable and if you just stay on the realistic side there should not be a reason not to succeed.