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.0