when deeply interested , nothing else creep into the mind- recollect past memories, as kids when you needed the toy, sweets, later when you needed your favorite food, even more later when in romance –the thoughts-mind were engrossed totally .,there was no room for any other thought. Or when ,run you made fearing a snake or dog. Or… Or even the wood you eat when U were really really hungry
If the golfer is deeply interested in the shot in hand to destroy the target. Mind will not have room for any other thought than destroying the target with the tiny ball. THAT'S THE ONLY JOY. Make the target your urge to destroy, like in the battle where your life is threatened if you failed to get the enemy on target.
There is no other mental training needed. Get interested in shooting.
Develop hunger to shoot at target. Golf is a target game not a dance at the stance .How you do -matters very little if you hit the target.
PRACTICE ( do things ,play other games,break routine, not allow rusting) TO BE HUNGRY TO PLAY --EVERY THING COME RIGHT -Over practice too is bad,Under practice may allow rust.Get the right combination ,Practice, breaks, physical training, other complimentary supporting game etc etc WAY OF LIFE that support best perfomance