Study the Lie of the Ball

From a short chip to a full swing, if the entire ball lies below the top of the grass, you will need to make changes in your set-up and swing.  You need to produce more of a steeper swing to get the ball up out of the grass.  Two keys that help first place more weight on your lead leg at your set-up.  Second, you will need to more actively and sharply hinge your wrists at the start of the backswing.  Keep your weight on your left foot and attack with a steep downward swing.