Pinch gripping involves squeezing the extended fingers towards the thumb without flexing individual digits, such as you'd experience holding a textbook.
Most strength athletes use plate pinches (holding two 25 or 45 pound plates together), but there are alternatives. For example, using two dumbbells allows you to have access to a greater range of weights. That makes it much easier to progress in smaller increments.
Maybe you're a bodybuilder through and through, but you still ought to know how to do some of the "old time" training methods like the split style. Besides, it may just put on some muscle, and that ain't bad.