The key feeling to have during the backswing phase of your swing, is the feeling of coiling and loading up behind the golf ball, in order to generate power for your downswing.
As you turn your body weight to the right, for the right-handed golfer, you should feel how your right leg loads up with power. The right leg should remain flexed to the same degree at which it started in the setup position. The bodyweight should be loaded to the inside of the right leg, as the shoulders turn above the right knee.
In the downswing phase of your golf swing, if the weight has been loaded correctly, it can now be powerfully unloaded by driving the right foot into the floor, which will in turn shift the body weight to the left hand side and allow the hips to unwind quickly towards the target. This action can feel similar to a sprinter pushing out of the blocks and running towards the target.
If your body weight is loaded to the outside of your right foot or your right leg is extending and locked out in the backswing, it will feel significantly reduced in the amount of power that can be generated using your legs in your downswing.
If you feel that you suffer from a lack of power, poor balance or are often leaning back after you have hit the golf ball, consider how the incorrect loading and unloading of your right side maybe the main area of concern.