If I tossed you a golf ball and asked you to toss it right back to me, without even thinking, I bet you'd throw it with your dominant arm. What this should tell you is that even though you've got two arms, you feel more comfortable using one over the other.
Remember that when you swing the golf club. A good golf swing is a blend of coordinated movement from both sides of the body, but it's really your dominant side that wants, and should, dictate the action. For most of you, that means taking a right-side approach to your swing. Grab a bath towel and I'll show you how. – With Ron Kaspriske
BACKSWING: LOAD AND SEPARATE
Wrap a towel around your right arm at the elbow joint and hold it taut like I am here (above). Now mimic a backswing all the way to the top trying to resist the movement—just a little—with your left hand. You should feel like your upper body is coiling with the latissimus dorsi "lat" muscle really flexed on the right side of the back.
You'll also notice that to swing to the top, you have to let your right arm separate from your upper body. I know you might have heard to keep that elbow tucked when you swing back, but letting the right arm "float" a little away from your trunk provides a nice, wide swing arc and puts you in position for the proper shallowing of the club on the way down. Essentially, you're creating more room to swing from inside the target line. Couple that with the coiling the resistance of the towel promotes, and you're poised for a powerful, right-side-fueled downswing.
DOWNSWING: SHALLOW AND CONNECT
Keeping the towel stretched, I want you to mimic a downswing. Get things started with your normal lower-body action and then pull the towel toward the ground with your left hand while lightly resisting that motion with your right arm (below). Feel like the right arm is moving down in the same manner it would to skip a stone or throw a ball sidearm. In other words, the right palm should not be facing downward. You should feel like the right arm is being pulled into a tucked position alongside the body. Why do you need the towel? When you resist the pulling action, it prevents the right arm from drifting away from the body toward the ball. That's the over-the-top move slicers make with the club cutting across the target line. If that elbow gets tucked and you keep rotating toward the target with your body, you're going to give the ball a strong smack with your right arm.