should i use a continental or eastern backhand grip. these are the shots that either seems to work with but which is best: serve? 2handed backhand? one handed slice backhand? and volley?
Umm, well...
Serve: By default you should be using a continental, but if you hit primarily kick/american twist serves, trying out the eastern backhand might benefit you (as it does me, I hit american twist serves 95% of the time).
Two-hander: Bottom hand should be continental, top hand can be an eastern forehand or semi-western forehand grip, whichever is more comfy.
One-hander slice: Continental, hands down.
Volley: This is where the definitions seem to blur, but I'll try to get through it with the least amount of controversy. You should use an "Australian" grip (modified continental being the modern term), which basically means a continental with a slight, and I mean slight, shift towards an eastern forehand (by no means an eastern forehand though).
My best advice for learning these grips is to go to an actual coach, but if you don't have the money/time for this, post pics of your grips if you're not sure.
Hope this helps!