jfinet, my grip on XD's is completely messed up compaired to other semi-auto's.
I pull my three lower fingers in to my fist pretty good/firm....and as if I were trying to pop a cigarett lighter open from the thumb pressure against the upper grip frame, and almost making contact w/slide (but I never make contact w/slide) my left (support) hand wraps around the right hand fingers, and left thumb aims forward.
It looks stupid with my right thumb sticking straight up in the air, but man does it make the XD stable in my mit, (even one handed/off hand) and like others have stated if you can hit when you aim....you got it licked.
Good luck/have fun...Bud