Many players release incorrectly because they can not physically produce the internal rotation of the hip needed in the downswing and release, use this quick half minute stretch before playing to work on your hip flexibility and allow your body to make the proper swing
The two most common bunker problems are allowing your club to hit the ball instead of using the sand as a cushion and allowing your spine or stance to tilt back which causes the club to enter the sand too early
Open your clubface, aim left and swing outside in