I'm not that good with girls, but, I do know that you should just, well, you know, hang out with her and her friends, maybe bring along another friend (but that has a slight risk of the target to like the friend), and so on. Don't be afraid to talk to her often. Possibly text/call, sit slightly near but not to show you have a crush on her. You must be...mysterious. Don't go overboard on it, just sort of be friends, you know. Don't listen to the guys just trolling and telling you to love her up. That is not the key to love.
...Damn, I should use this info on the girl I like. :o