Even a touring pro may play with a swing key or two.  For example i may have a ‘key’ for my backswing and then another for my downswing.   I’ve begun playing again and my badshot is an ‘over the top move’ = where i start with my hands at the same time that I’m driving forward with my legs(weight shift).   This will cause my club to go out ‘over the top’ and i will attack the ball from outside to in.  Not a good move which many golfers have, usually making a big slice.  In my case i pull the ball to the left because i get the clubface square, but my hips haven’t yet cleared and the out to in clubhead will launch the ball left.

So i will set up with a slightly narrower stance and put some weight in my right inner thigh and instep.   I will make the backswing with the thought of adding more of my weight to my right instep – and once i feel the top of my windup(backswing) i will then dynamically push off of my right instep (the ball joint under my big toe) trying to get my weight to my left heel as fast as possible.   This keeps my lower body initiating my downswing and the hands and clubhead will drop inside allowing the left hip to clear first as the club meets the ball square for a straight launch.