For me when I used to play alot (just getting back into the game after a 20 year hiatus), using a soft relaxed grip...
One thing really helped my game a ton, I severed a tendon in my non dominant hand, and on my first league night playing after it happened, i assumed I wouldn't really be able to play, match came up, I fumbled around on my first two shots then realized my only choice was to play one handed.
I won all 5 of my games that night, and a good portion of other matches after...what that really did was made me shoot softer, and inturn more percise and consistant, it did mess up my game once my hand healed trying to go back to playing with both hands, but that eventually also came back, playing that way got me alot of strange looks but taught me alot in those 10 weeks.
Now I need to relearn it all, so this was a great grip reminder...thanks mytheory...