Trying to hit a golf ball while off balance is as hard as it gets. When watching a good golfer the easiest thing to recognize is how they remain in balance throughout the swing. Most amateur golfers have trouble with balance throughout the entire swing. Often times you will see people having to step out of the golf swing because their balance is so bad. While many golfers can set up to the golf ball in balance they often lose it quickly during the swing.
There is a very simple drill that is very effective in the development of dynamic balance, or balance during the swing. On the driving range set up to the ball with a narrow stance and lift your right leg, for right handed golfers, off the ground. From here simply hit golf balls. It is best to start out small just hitting pitch shots and work your way up from there. Chances are you will quickly see how off balance you get from the very beginning of your swing. Practicing this on a regular basis can help develop sound balance and greatly improve your swing.