Two moves to get noticed: return her smile, then fix your posture. Pull shoulders back, stand taller, keep your head level, stay open. The point is looking confident but approachable, not creepy.
Okay, the second thing you should do. So number 1 is to smile back. Number 2 is to do a quick little mental body language scan of yourself. What do I mean by this? Just take notice. Are your shoulders back? Could you stand up a little taller? Keep your head not too high, not too low, just straight on. Make sure you're open and friendly. This is kind of creepy. Instead, you want to put your best foot forward. You want her to say, "Oh, he's cute."
