Hey Peissea
If only we guys really knew the secret... I would recommend my method which usually works most of the times I try it. be yourself and be confident. what I mean is, when I approach a girl I don't think about what I am about to say, I usually walk up to her and say what's on my mind.. things like "I've been standing here with my buddy for a couple of minutes and couldn't get my eyes off of you.. what's your name"
The important thing is to be confident about yourself, and to be direct and forward.. I can't promise anything but I think that's what most ladies would appreciate.
Cheers and good luck..