Here’s a good drill for establishing sound balance within your set up prior to taking your golf swing. Take a couple of inflatable disks to stand on, mimicking unstable ground.
The goal of this exercise is simply to find good balance both left and right and heal to toe. Go through this exercise a few times to reestablish yourself, each time making sure you have a good bend in your pelvis at the hip joints and sink down into your knees a little, ensuring that your chest is facing the ground. Move the club around like you would standing over the shot each time as well.
Once you’ve gone through this a few times, take those feelings in your feet up to the golf ball, find the same characteristic as in the setup, and take your swing. Establishing that balance at the beginning of the swing leads to a better dynamic balance throughout the golf swing.