Learn to take a divot in front of the ball by finding the three bottoms of your swing, fat shots are caused by using too much back arm and results in a swing bottom behind the ball
Turn your body, not your shoulders, in the swing to create a coiling effect in order to generate more power
The position of the ball in your stance is determined by your swing shape and the club you are hitting. Your wedge should be near the center of your stance and your driver should be off your front heel.