Basic technique: In chest-deep water, put your hands out in front of you with your fingers straight and close together. Turn your palms out and sweep your hands and forearms out to the side beneath the surface, then turn your palms in and sweep back to the center. If you scull continuously, you'll be tracing an elongated figure eight.
Back float: Lie on your back with your ears just under the water. Move your hands close to and just under your hips, using the figure-eight pattern, with your palms facing upward as you scull toward the surface and facing down as you scull toward the bottom. If necessary, add a flutter kick. An excellent warm down, this motion also helps you "feel" the finish of your backstroke.
Canoe: Lie facedown with your back arched slightly. Your head should be out of the water with your heels just breaking the surface. Place your hands at your sides and move them in a figure-eight pattern, as you would in back-float sculling. Use this to practice follow-through in freestyle and butterfly.
Catch-up: Lie facedown and extend your arms forward over your head. Scull in a small, outward circular motion, with one hand at a time or with both. This is good practice for the "catch" of your pull in freestyle, breaststroke and butterfly.
"S" pull: This motion, used in freestyle and backstroke, is really just a big scull. You can perfect your stroke technique by slowing down and analyzing your movements, making adjustments as necessary.