Squat and place both fists on the ground behind you or at your sides depending on where it is more comfortable. now move the fists on the ground like zig zags using the wrist to move the hand around. once you feel your wrist is full and you your shoulders relaxed and aligned with the rest of the body move your mass to the fists till your legs are off the ground and back again a few times. This is a good way to make the wrists more healthy and full and to learn to push better in different ways which is the first step to good deep hitting.
Have fun and smile from time to time.