With a good lie, the ball should be placed left center in the stance. The stance itself should be very open, with you half facing the target. This allows you to open the face of the wedge and use the "bounce" or the flange of the club. Now aim at the area behind the ball (approximately 1 1/2") and swing through, taking a divot of sand. The ball will be in the middle of the divot and come out softly. The distance the ball will travel depends on the texture of the sand and how hard you swing.
With a buried lie, the ball should be addressed off the right foot, and should assume a square stance. The blade of the wedge will be hooded (or closed). You simply swing the club up abruptly and drive the leading edge of the wedge into the sand about 1" behind the ball. This chopping action will force the ball up and out of the trap. This shot is very unpredictable as to the amount of roll. Your expectations should be realistic.
Fairway bunkers are as often placed for protection as they are for penalty. Often a shot that is hit astray will be saved from going into the woods or a hazard by a fairway bunker.
Club selection is the key: choose a club with enough loft to easily clear the lip of the bunker.
For good execution, the ball must be struck cleanly. Follow these three tips for good contact: