Concentrate on the stretch right down to the toenails. Knees tight, but not rigid. Ankles as loose as possible. Toes pointed like a ballerina. Alternate pushing toes down about 4 inches toward the bottom of the pool (then relax that foot, while the other pushes). Rate is about 2 to 6 kicks per stroke. Allow a little roll. If your feet are coming out of the water, then you are kicking up. Your propulsion by kicking air is zero.