Seemingly simple pitch shots that you end up hitting only a foot or two because you scoop under the ball instead of hitting down on it.
The Silver Lining
The reason you muff short pitches is that you stop turning your hips on your throughswing, which causes your left wrist to break down and sends the clubhead flipping out in front of your hands. On most shots, wristy impact is a recipe for disaster. However, when you have to pop the ball high and soft out of greenside rough, you actually want to flip your wrists.
Get it Close by Getting Wristy
Set up with a slightly open stance and play the ball slightly back of center. Take your regular pitch backswing, but as you come back down, slow your arms and hips (something you do anyway if you often muff pitch shots) and quickly break your wrists through impact. Don't allow your arms to pass your body. If it helps to think of folding your left wrist or bowing your right, do it. At the finish, your right hand should hide your left. While this is the opposite of traditional short-game advice, it's exactly what you need in this situation.
Why it Works
Flipping the club past your hands increases the effective loft of the clubface. So you get extra height on the shot you normally wouldn't get if you adhered to the standard advice of keeping your hands ahead of the club at impact, which most recreational players do as often as Tiger misses the cut. Plus, deceleration is common on short swings, so you don't even have to practice this shot. The technique works with any of your wedges, but to hit the ball extra high and help it land soft (don't expect much spin with this technique), use your lob wedge.
Don't Try it When...
The wrist-break flop shot requires perfect timing and has zero margin of error from a tight lie, so unless you have a fluffy lie in greenside rough, don't attempt this shot.