Yeah the number one thing when approaching is the GO IN BOLD. Do not be unsure. Keep it light and funny. control the convo but make it look like she is in control. Then MAKE SURE YOU CLOSE. I repeat: MAKE SURE YOU CLOSE. If possible, stay away from open-ended obligations (give me a call sometime!) in lieu of something more concrete (ok, if you don't call me by 6:30 I'mma call you at 7).
Finally, let the game come to you. One thing that is often overlooked on this site (and by most people in general) is patience. Frustration and impatience has foiled many a pick-up. Let me know how things turn out.