This drill is especially good for people who tend to reverse pivot or tilt their upper bodies towards the target on the backswing. It is a reminder to load you weight into your back side at the top of the swing. It will also help you build muscular strength and endurance.

Assume a golf stance with or a golf club.
Make a backswing and stop at the top making sure you keep your back knee flexed.
Squat down at the top of the swing, then return to the start position.
Repeat for 8 to 10 repetitions.