Just had this long discussion with a booker in NYC. (Yes, that's a B on booker).
Any gift is appreciated. My favorite thus far has been a DVD of The Quiet Man (my favorite movie).
Tipping is appreciated, but the best tip, the best review is a return visit. Out of all the ladies out there you chose to see me ...again. That's the best anything. (mainly because things only get better with familiarity)
+1 with Babee
since a gift is something voluntarily bestowed upon a person it should be your choice.
Babee is right, The best tip is if we had a good time then come back, and that's my tip to you Pickupkid
Cash tip is always preferred, but I have been given many wonderful gifts, some of my choosing, and some were simply a nice surprise. Tipping is always appreciated.