I've read and heard that raising your eyebrows is overcompensating. I don't know but to me it seems like the opposite. When you raise your eyebrows, you come off as more natural and engaged in the conversation with the girl. I'm not saying to maintain the raised eyebrows, but I have to say that raising your eyebrows does improve your confidence. If you never raise them, it seems as if you come off as less believable. When I raise my eyebrows while talking to a girl, it kind of gives me the sense that I'm more superior. A girl even told me once, "Stop raising your eyebrows like you're smarter than me".
Here is what I mean (where Will Smith raises his eyebrows):
http://www.youtube.com/watch?v=jUdwCQ8t_R0
Another point to bring up is flirty body language. I have tried to use flirty body language with girls in order to put them in the flirty mood but it just doesn't work. Flirty body language in general is basically going in and showing interest. I would do that by leaning in, turning with my whole body towards them, staring at their lips only, etc. I thought all of that would put them in that flirty frame. BUT for some reason, using asshole body language like raising your eyebrows and giving them the "fuck off" look, it makes you appear as uneedy and interesting. Flirty body language to me just seems like saying, "I like you. I am now giving you my full attention as I'm trying to hypnotize you." I mean if a girl came up to me and began to talk to me while looking at my dick and twirling her hair around, it would just feel like she is too easy to get and that she's coming on to me.