Check the Sand and Ball Position
There are clues to how tough this bunker shot is going to be. First, did your ball bury itself in the sand? If the sand is fine and dry, it will be much easier to get your ball dislodged from the sand and hit the green. If the ball is sitting up in the trap, that means the surface of the bunker is probably hard. A hard bunker can make hitting the ball close to the pin very difficult.
Dig Your Feet In.
Position yourself for the shot. Balance is really important when it comes to sand shots. Because the ground underneath your feet is less than solid, swinging a club can throw your body weight off, resulting in a poor shot. Set your feet shoulder-width apart and then increase that distance by an inch on either side. Now twist with your feet and hips, digging down with your shoes until you feel entrenched in the sand. This will allow you to swing with confidence.
Pick It or Blast It.
Decide whether to "pick" the ball or "blast" it up and out of the bunker. Picking the ball is the ideal method for hard bunkers and long flat greens with little slope. When you pick the ball you swing as if you are hitting on a normal fairway, trying to get just under the ball so as not to bring too much sand into the equation. It's a nice, clean hit, but your ball will tend to come out a little hot, so swing with care.
If the ball is buried or you need your shot to drop the ball and have it stop, hit behind the ball about an inch. This is called blasting it; the objective is to use the sand to soften your club's impact on the ball, resulting in the ball coming out of the trap in a high, soft arc. This will allow you to place the ball close to a bunker-side cup. But be careful: too much sand, and you'll get to do the shot all over again.