Please remember this, boys.

If you want a girl, make sure you really want a girl, and then go all-out in your sexual aggression. Last night, I was in a club with a girl that I thought might have friend-zoned me. I wanted to 'test the waters', so I started half-heartedly grinding on her. She moved away. I then tried again, but with the idea in my mind that I very much wanted her, and that I was going to show all of this. I started pulling her really close around her waist, grabbing her hands and putting them around my neck. In short, I made it so that there was no doubt that I wanted her. She responded very well and we eventually made out.

tl;dr don't half-ass showing interest.