Most Helpful Girl
I don't really give signs.
If I want to talk to you then I'll go over and talk to you or smile at you and wave you over.
Most Helpful Guy
Ugh, there are plenty of signs, but I'm really not in the mood for a dissertation. Let me keep this short.
No one sign is foolproof. There are some that are somewhat reliable a decent percentage of the time, but they are not universally true (eg, eye contact and the way she breaks it--up is annoyed with you, to the side neutral, down is submissive and she likes you), and they have plenty of exceptions.
If you fancy a girl, talk to her. Don't think, just go. Stop second guessing yourself. Signs are great, but they won't always be there. Just assume she's attracted to you and ask her out.