Hitting the ball fat tends to come from either falling backward on your backswing or overusing your hands and uncocking your wrists too early
Select clubs for your bag based on your game, if you are a beginner stay away from the high lofted wedges and stick to more hybrids while the advanced player should have interchangeable clubs that he selects based on the course and conditions he is playing
Hit closer to the ball using a normal backswing and accelerate the club on the way through