Better players should understand how the bounce and belly features of a sand wedge affect trajectory. A club has bounce when the back edge of the sole is lower than the front edge. This causes the club to "bounce" through the sand. The belly, or the low point on the rounded bottom of the clubface, is slightly closer to the heel. When you flatten or lower the shaft, you access the bounce and belly and promote a shallow approach -- two factors that help elevate the ball.
Take your standard address position (1), then flatten the shaft by bending more from your knees and hips and lowering your hands (2). Make a normal backswing, and focus on swinging the shaft through the same angle you created in the setup. The lower your hands are at impact, the higher the trajectory of the shot.
SPECIALTY SHOT: UNDERSTAND THE PLUGGED LIE
To control your ball out of a plugged lie, respect physics and realize there's no need to swing very hard to extricate the ball. The situation is much like a flyer lie from short rough: The ball comes out with very little backspin. That lack of spin will make it run hard, so you just want to pop it out and let it go.
Grab your sand or lob wedge, take a slightly open stance and close the clubface a little -- this will set up a digging action (above, left). Make a full backswing and then bury the clubhead in the sand about an inch behind the ball (above, right). Don't follow through. In fact, try to leave the clubhead down in the sand. The cushioned blow will force the ball out, and the lack of spin will produce plenty of roll.