You might not believe it now, but there will come a point when you think getting out of greenside bunkers is easy. When that day arrives, turn your attention to improving your control of the ball once it lands on the putting surface—especially on short sand shots.
When you need to stop the ball quickly on a green, you have to create a fair amount of clubhead speed. But if you try to get that speed by making a standard-length swing, the ball will fly too far. Instead, you need a fast swing but a short follow-through.
You've got to hit the brakes once the club enters the sand. Momentum will still carry the clubhead toward the target (above), but the finish will feel very abbreviated. This fast-but-abrupt swing imparts enough force to get the ball out of the bunker, but it won't go very far past the lip once it lands.
The key is committing to making an aggressive downswing. Don't be afraid that the clubhead speed you're creating is going to shoot the ball over the green. If you enter the sand an inch or two behind the ball and let all that acceleration dissipate just after contact, you can trust that the ball won't go very far. Having that kind of touch in the bunker will have your friends calling you the Sand Master. — With Ron Kaspriske
You need even more speed to get the ball up quickly when your ball is on the upslope. The lip is just too close. The problem is, you often can't create enough speed just with your arms. You have to add more oomph to the shot, and you can get that if you use your body weight. try this: As you swing into the sand, step down the slope and away from the target with your lead leg. This change of direction thrusts a significant amount of energy toward the target. Your body goes one way; the club goes the other. The ball will pop straight up and fly just far enough to get you on the green.