This greenside bunker video by short game specialist Phil Mickelson, and is one of the best videos you can watch, no matter your skill level. I personally think this caters a bit more to the more advanced golfer, but the tips and basics are good for any golfer to watch. Hitting out of a greenside bunker induces an anxiety among golfers that is almost incurable at points, and I have found that confidence is the only way to really cure it. He shows you how to use the mechanics and shots that you already use to get out of the bunkers more consistent.
What I love so much about the video is that he does not go into inches behind the ball and angles, which I think is not important. What is important in bunker play is getting in a bunker and moving to all the different lies and just hitting a bunch of balls out of there. Once you practice it over and over again, you will learn exactly what you need to do in each situation you arise. All bunkers are different in that they have different shapes, lies, sand type, sand thickness, etc. The same method on one bunker will not work in the other, so learning the basic mechanics is better than memorizing where to hit behind the ball. Anyways, I am rambling, so just watch the pro in action here!