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.
Fitness is filled with workout challenges and WODs. And most of them are stupid. Here are three smart ones that take only 10-15 minutes. Bonus: How to design your own.