Practice teasing with your friends... both male and female works. I'm using quite a lot of stuff I got from talking to one of my best (male) buddies... we can bug, annoy, dis and neg each other for hours. He's a little bastard
A funny one though! ...and guess what? This stuff works great on women! Treat them as your slightly retarded little sister! In a playful sense of course.. don't be a jerk! Find her boundaries and don't push things too much. But yeah, treat her like she's a funny distraction, but not really worth much of your attention... Make her feel like she's got something to prove, that she has got to have more than just looks going for her to get you interested. The hotter the woman, the better it works. 
Try to feel her mood and ease up a bit on the teasing if you think you've gone too far Being playful in a confident way almost always works though.