When you swing the club, you basically want to swing the club up and down with a cocking and uncocking of your wrist with a little torso turn. A lot of golfers try to pull on the club in the downswing. That is not the kind of motion you want in a bunker shot. You want the clubhead to move the most and fastest. It is like the club head would pass the hands through impact. That allows the bounce of the club to hit the sand and adds loft to the clubface. It is like snapping a towel. If you move both ends of the club you can't snap the club through. The most important part of holding the club is the cupping of your left wrist. This cupping action adds loft and bounce to the club.