If you can't hit your woods off the tee–or when you do hit them, the ball slices uncontrollably–chances are that your downswing is too steep. The reason this occurs is that the clubface can't return to square when it comes down so vertically, and the open clubface creates a slice.
To fix this problem, perform what I call the tall tee drill. Take a fairway wood or small-sized driver. Tee the ball so that the entire surface sits above the face of the club (you may need the longer 2 3__ã4-inch tees to accomplish this). In order to hit this ball solidly, you'll need to make a more sweeping downswing. Your goal should be to hit the top of the tee and the golf ball simultaneously. This will produce better contact, and because the shallower downswing will allow the clubface to more easily achieve a squared position, you'll hit straighter shots. You'll know if your downswing is too steep if you pop the ball straight up in the air or miss it completely.
When you go on the course, tee the ball only slightly higher than normal until you're comfortable hitting from the taller tee.
Rob Stock is an assistant golf professional at Farmington Country Club in Charlottesville, Va. Stock also is a certified golf fitness trainer.