I.A.F.Y.B.
Master Don Juan
Once you think she feels comfortable around you, and if it would be appropriate time; given the current situation, ask her if she is ticklish. If she answers yes or maybe, proceed with the tickling. If she answers no, say "I think your lying" and proceed with the tickling. From observations, I would say that eight out of ten girls are ticklish. Plus, if she really likes you and is truly not ticklish, she will fake it anyway. Tickling is a very good trick to use because it involves touching, (kino) and you should touch her whenever possible. Usually women respond very well to this, as long as it's delivered in a respectful manner (no a$$ or boob grabbing people).