Bunker shots should be controlled almost entirely by your arms, not your body. This applies to nearly ever bunker shot, from fairway to greenside bunkers. This especially relates to bunker shots from uneven lies. Why? Well, for the same reason that you dig your feet into the sand in the first place… balance and stability. Sand is an uneven, unstable surface that you’re attempting to perform a very dynamic motion on.
I see plenty of amateurs attempt to scoop the ball out of the sand, with a very active lower body in hopes of getting the ball airborne. The results are erratic, a skull here, a chunk there, regardless, the ball rarely leaves the bunker in one shot. Consistency creates confidence and stability in the sand is the key to consistency. Imagine your lower body is incased in concrete when you perform your stroke. As long as your spine angle doesn't change from address to impact, you will <strong>always</strong> hit the shot solidly.
Play the ball forward in your stance, and aim to the left of your target slightly (setting up open). Open the clubface and dig your feet solidly into the sand until your weight is evenly distributed. Flex your knees and stand a little further from the ball than normal. Focus on keeping your lower-body silent throughout your stroke and accelerate through the sand to your finish position.
Give it a try!