Don't worry, totally clean topic, despite the title.

When you have chemistry with someone, you feel it, you see it in body language, the way the other person holds your gaze, maybe a little bit of playfulness in their smile that tells you "You know what, I think I like you." That gives me trouble though, I've come to realize I have difficulty flirting. I'm great at being friendly but awkward at romance. I'll meet women and we'll hit it off great as buddies but she just doesn't see me 'that' way, which is totally cool, I can respect that she isn't interested and keep things status quo, but I really would like to change somewhat, at least to make up for this attractive factor I seem to be lacking.

So the question, for guys, when you're on a date with someone or getting to know someone, what works for you? What do you do to ignite that spark of interest? And for girls, when you're on a date with someone or getting to know someone, what have your dates done or these new friends done that changed your point of view of them? What sort of things turned you on about them or made you think of them some time later, long after they had gone?