Trying to relate this to another thread. I realise that I hit the most consistently when I try to keep my left hand straight (and it hardly gets as straight as I imagine), and using the left hand to swing down/round. I think perhaps this helps me to have a nice round swing down. Result is a fast downswing which seems to take control of itself, but I am able to hit the ball sweetly in most cases when I do this. If I let my right hand take control, or try to "hit" the ball, then all sorts of problems appear...