Well definetly don't ask to kiss her. Its a mood killer. Best bet is to initiate the kiss and see how she responds. If she cowers in fear and begins to howl like a Mongolian, then odds are you're SOL. If she returns the motion, or sometimes remains still, you're golden. Just don't go in tongue-blazing, gripping the back of her head and whatnot.

If the initial kiss goes smoothly use your instincts to see what comes next. It might lead to a hookup or it might lead to nothing. Be prepared for either.