Body language can be everything. You see her from across the room. She gives you a head tilt and smile. This is one of the classic female body language clues. The head tilt offers submissiveness (like a wolf baring its throat to the Alpha) and the smile is an alluring and reassuring invitation. She wants you to make an approach and is willing to accept your lead. To learn more clues about female flirting, read on.
Ways to read female body language: the hair
The most obvious technique is a woman's hair. A woman's hair often defines her as a woman; it is a fairly common cultural thing. Many women will also use their hair in flirting and also unconsciously use it in their body language to indicate desire for attention and flirting. The first way is the head toss, which readjusts her hair. Since hair length and beauty is often seen as a primary trait of womanhood and beauty, by doing this she is saying, "look at me, are not I beautiful" Another clue is playing with her hair. If she is putting it behind her ears, she is baring her throat (again, submissive). If she is twirling her hair, it is a sign of nervousness and could mean she is scared of saying something wrong and losing your interest.
Girls body language clues
Another big clue is what she is doing with her hands. Women often externalize what they are wanting inside to objects they play with their hands, when they are nervous. If she is rubbing her finger or an object (say a pen or a swizzle stick) around her lips, this shows that she desires to be kissed. If she is rubbing her hands or fingers up and down an object slowly (like a glass) this indicates that she wants to be simply rubbed or stroked.