If you are talking to someone in a bar that you are interested in hooking up with, here's a trick to try when you are talking to them. Lower your voice a little bit. If you talk a little bit quieter than usual, they'll have a hard time hearing you and, if they have any bit of interest, they'll lean in to hear what you are saying. This creates a much more intimate conversation, they'll feel like they are having a better conversation with you. It won't make much of a difference if they have no interest in you already. But it's one of those little tricks that might just put you over the top.