Well, for me, my now girlfriend, the only one I was actually sure was interested in me from right off, she did so much hair tossing that I thought it would fall off. Also always smiling when I was around and the looking away when I busted her sneaking a look and the shy smiles that came after that, not to mention the nervous giggling.
Well I was pretty sure she was interested or maybe I didn't care anymore at that stage. Whatever! its worked out fantastic for 3 years now and no regrets
They listen to your words like they are the most important words ever spoken.
I know it is just the first ex
i can never tell myself, but if i am that curious i get to know them better.
There are a number of physical clues (playing with their hair, dilated pupils) and verbal clues (slightly risque chat), too many to list here but it's something for you to read up on.
If in doubt, ask one of her friends if she fancies you.
I don't think there are any hard rules about this. All women are unique, and go about things their own way. Some will draw your attention then go coy. Others will be in your face to the point you may find them annoying.
If by chance a girl does something totally out of character and may be a little embarrassed but not regretful the feelings may well be real.