There is no 1 way to talk to a girl... but if there was it would be this - Go up to them and say, "Wow. You look exactly like my girlfriend", and go on to tell them how their hair is the same, their eyes, nostrils, whatever. Just act really shocked when you do it and be funny. And after a few minutes of this, you can just say "you know what? I don't have a girlfriend", and as long as you haven't freaked them out, they won't care, they'll even think it's funny. Then talk a little bit and ask if she has a phone, don't ask for her number, just ask if she has a phone, then when she whips it out punch in your digits and get her to call you then and there. And put your name in as something like 'lord of sex' This is a surefire way to get her real number in a not so obvious way. Only do it though if you feel confident that you won't mess it up, otherwise you will freak the girl out. But either way, in doing it you will learn something.