The beauty of golf is that even after years and years of experience you still can learn something new every day. Here's a tip I happened to pick up while watching golf on the television.
When you are in the sand trap and the sand is soft, it's recommended that you dig into the sand by wiggling your feet to sink down and get a firmer stance. A subtle side effect of this approach is that you end up slightly deeper below the ball compared to a normal stance on firm ground.
In order to compensate this sinking below the ball you need to adjust your grip by choking down slightly, resulting in an inch or two to the top of the grip being exposed above your left hand.
For optimal effect this distance should be exactly equal to the amount your feet have sunk down in the sand. You take a normal swing except that you're gripping lower and the arc is at a sharper angle. You need to strike the ball at the point just above the spot where the level of sand meets the surface of the ball.
Hitting a ball smoothly out of a sand trap taking just the right amount of sand with it is a fantastic feeling.