When your ball lands in a bunker, you don't have a solid method for getting it out. Your two problems are that you either chop down into the sand behind the ball (burying the clubhead too deeply and failing to get any loft on the shot), or you make a swing that's too shallow and blade the ball into the face of the bunker. In both instances, you're unsuccessful in escaping the sand, and it's costing you strokes.
The bottom line is, standard bunker shots are not that difficult once you have a reliable method you can use every time. My simple technique has worked for me on the LPGA Tour and will work for you as well. Here's how to do it:
Make sure you set up with the ball well forward in your stance, just off your left heel.
Make a short, compact backswing with minimal shoulder turn, so that your hands are no more than waist high. Hinge your wrists to create a 90-degree angle between the clubshaft and your left arm.
Swing down steeply by pivoting your hips, but keep your hands and arms close to your body. Allow your wrists to unhinge fully and then hinge again after impact. This hinging and rehinging action will get your clubhead through the sand easily and create plenty of loft on the shot.