How do you talk to girls that you don't really know?

i'm quiet a confident guy not to be big headed but I have no idea how to start conversations. it always the same " hello how are you, what you been doing?"

There's always the old lines, "Where have you been all of my life" or "What's a nice girl like you doing in a place like this?" :-)

Seriously, if a girl is interested in you, most anything you say will get a positive response and if she isn't, there's little you can say that will make a difference. What I'm saying is girls are seldom attracted to the words that come out of your mouth. It's the way that you look, your attitude and demeanor that works. Being overconfident will often work against you. Try being humble and telling her you're shy. That will make her feel comfortable because she probably feels the same way. Some guys can be so confident they're scary.