Good luck with that one... I have been tyring to figure that one out for about 17 years. I still havent got it.
I do know this however, girls do not like just one type of guy. DIfferent girls like different types of girls. You just have to get to know the girl in question and attempt to figure out their taste. (Of course, by then it may be too late.)
Well I can tell you this, don't be too obsessive with them, or too overbearing. Just act like yourself, not like a bad ass or anything like this, but don't be too emotional. Try not to be too cocky either, that is sorta bad, lol.