We men are visual creatures by nature. Each of us has some things that turn us on and off when we're looking at your showcases. Because there's so many, we frequently have to whittle down the options and often something minor can be the difference between getting a friendly PM and being ignored.
One thing that turns me off, no matter how hot the girl is: dirty feet.
I've seen more than a few of the hottest girls on here put up pictures where their feet looked like they were working in a coal mine barefoot. It just makes me feel like you don't give a shit about being clean.