Avoid "swaying" drill
Found this bit of help on the internet the other day, something I'm probably guilty of myself - hopefully of help to others... Any thoughts on this or other ideas chaps???
"One practice drill that you can do in your back yard to learn to shift your weight, instead of sway it, that does not even require hitting balls is to get a couple of quarter-inch diameter wood rods that are long enough to be waist high after you push them into the ground (3 to 3 1/2 feet long). You can buy them for very little at your favorite hardware store. Push one into the ground about an inch to the right of the back part of your right foot when you take a stance like you are addressing the ball, and one about an inch to the left of the back part of your left foot. If you have set it up correctly you are now pretending to address a golf ball with your normal stance, and you have two wood rods pushed into the ground in such a way that the top of each rod is about even with your waist and they are positioned just outside the heel of both your shoes respectively. Then take some practice swings. You should be able to make a complete swing without touching the rods with either of your hips or with the outside of your knees. This drill will also help you learn to make a full turn in your follow through while maintaining good balance. Do not stiffen up so much that you do not follow through. Just concentrate on shifting your weight to the inside of your back foot on your backswing, then shifting it to the inside of your front foot on your forward swing, while making a full turn at your waist without moving laterally during any part of the swing.
After a while you will be shifting your weight back correctly on your backswing but you will not be swaying your body when you do so. Likewise you will be shifting your weight forward correctly on your downswing but you will not be swaying in that direction. Just remember: shifting does not mean swaying! Now the concept of "coiling" your weight back and shifting it forward will make sense."