Since you can never ground a club in a bunker, it's a good idea to practice the technique you will use for this shot - and you do not even have to be in a bunker to do so. At the driving range, simply hold the club off the mat in the same way you would in a bunker and practice your strike, hovering the clubhead off the ground, then swinging and hitting the ball. You will quickly get used to making a good shot this way, and when you find yourself in a bunker, you will not be in such unfamiliar territory.