I've got to tell you guys the ultimate "no pre-shot routine" story that still kills me to think about. A good old friend of mine now--Mike Tiernan--from Delray Beach (Gulf Stream G.C. and Maidstone) was an excellent tennis player and a near All-America lacrosse player at UNC and he decided at maybe 30 or so to give up tennis and get into golf. He understands competition as well as anyone I know--he knows course management now as well as any one I know. He made a dedicated study of what it took to get good at golf--he hung out with some good players and picked their brains and observed them carefully when he was starting to learn golf.
But for some reason he never did learn the importance of some kind of "pre-shot routine" IF ONLY to get himself started to hit the ball. He used to get sort of locked up over the ball, sometimes just flailing around aimlessly and sometimes was unable to take it back--he'd back away, start again, whatever.
So one time on the 15th tee at Gulf Sream many years ago he got up to hit his tee shot and couldn't do it. He backed away, got up again, had the club sort of moving all over the place without any purpose. He backed away again, got up to the ball again, started sweating profusely and finally screamed "OH GOD!"
Now the guys he was playing with were experienced golfers, his friends, and we're looking at this in fascination and looking at each other in amazement. Finally, Charlie Neff, a very funny guy says to Mike; "Mike, stop that stuff and just go over there behind that tree and wack off because that's about all you haven't done yet!!".
Of course all of us fell on the ground laughing our asses off including Mike. And immediately following that we taught him the importance of a set pre-shot procedure to be followed the same way every time including some little starting key like a forward press or perhaps a little Gary Player left leg kick to get himself going. He did all that and has been a fine golfer ever since!