Re: Changing Grips - Tips?
Right hand should be in continental for two handed backhand. Just as Ezone describes. Pretty much all the top pros with two handed bhs do it that way. But if you aren't used to it, it will take quite a bit of work. Sounds like you are used to not changing the grip of the right hand at all, so changing grips during a rally will be a fairly big learning curve.
It will come in time, as Sean says.
You are meant to change grips between fh and bh, but if you aren't used to it this will take work, at first you will have to think about the grip change and you will be a bit slow. Practice changing grips with your eyes closed- you can get some practice of this even at home without a court.
Smyth, good players usually stick with one fh grip for all their topspin fhs, but they will switch to continental to hit a slice defensive fh or dropshot. Occasionally I have seen some players use a more neutral grip for return of serve. But basically a player has a single fh grip for all topspin shots.