Check out this instructional swimming video that demonstrates the proper techniques to practiceing the single arm drill. The single arm drill ensures that you are getting the rotation you need throughout your stroke. Push off the wall with both arms extended in front of you with your hands touching, one on top of the other. Rotate to your side so that you are lying on your left side with your left arm in front on you. Now, swim down the pool, using only your right arm - once you get to the other end, try the same thing, this time lying on your right side and swimming with your left arm only. Keep a strong kick going and focus on the pull portion of the stroke. Improve your swimming ability with this swimming tutorial video.