During the short sand shot it is important to remember four key points.
Club hits sand - Sand hits ball - Ball is lifted from the bunker. Therefore, your target is not the ball. Your target is actually a spot in the sand between 1.5 and 3 inches behind the ball.
Swing smooth, with even tempo.
Swing slightly steeper toward the sand. This helps the club to get fully under the ball.
Follow through - Why? - JUST DO IT.