Setup like you are addressing and imaginary ball, with your back foot about 3′ from a wall. Now, imagine you are in the middle of the downswing just at impact. Also, imagine there is an elastic band attached from your hands to the wall you are pulling on. If you just use your hands to pull on the elastic band, you will get “X” feedback about how powerful that is (old traditional release the club technique). Now, imagine you are pulling the elastic band by turning or rotating at impact. Your whole body is pulling the band equally and together. This is what usingand not just the hands feels like at impact. You have the “Mass” of your entire body and the “Speed” of your body rotation moving the ball. Plus, your radius is twice as long and the face stays square. Much more combined power. Much more reliability. Takes some practice to get the hands from taking over, but this technique is much more consistent once learned. I will shoot a video on this soon to demonstrate.
You could also setup with a club in a door way and simulate impact with a body rotation pushing at impact using your entire body for the same effect.