One for Each Foot
Put the balls in the floor. Place a foot on each. Press down on the ball. Try to flatten it. Let foot up.
Do the other ball. Foot on ball. Press down on ball. Try to flatten it. Let foot up.
Alternate Squishing - like Pedaling a Bike
Roll Ball Toe to Heel - Left, Right, Left, Right
It occurs to me that if I stand up and press each foot alternately, I have just gained a footstepper.