I think this is really important, because a look its probably the first type of contact that you have with a girl, and if it looks creepy you will probably will never get a good chance to get a conversation from her or her number.
when you look at us, try not be creepy like zoning into parts of our bodies or make any sort of gesture and facial expressions that might even seem creepy. Anything you might think would borderline creepy, it probably is. When we make eye contact with you, smile and make eye contact with us a little longer than a glance. If we smile back and keep eye contact (or quickly avert our eyes but then make eye contact) we're into you too. then approach us...don't just stand there and have a eye staring contest.
i am going to have to go with what they said before me. Whatever you do, do not just stare! that is beyond creepy! if she looks at you then you should just smile back, or maybe wave (not a full on shaking of the hand!, just a small gesture). If she smiles back (or waves), then you should go talk to her..if not, then you failed and you are now labled as a creep. But other than that most girls like the fact that they can catch a guys attention.
It's important for you not to stare! I can't even tell you how many times, guys stare at you and it's just creepy. So, if the girl you make eye contact with notices you smile, and then look away or start talking to a group of friends. And then in a few seconds look back and see if she's staring (: