Let's talk about some specifics with respect to visualization. First of all it is very important for your game, all the great legendary players in any sport use visualization. Watch a boxer in the ring someday like Evander Holyfield and you will swear there is someone opposite him fighting him when he is doing his visualization.
Why is Visualization Important in Golf?
Visualization is symbolic rehearsal of what is to come. Whether you are visualizing the path of your swing, the shape of the shot or whatever. It is very good in that it is lighting up the pathways in your brain from the muscles you are going to use in your golf swing. Visualization further enhances your course strategies. Sam Snead actually talked about blueprinting the course before you play.
Many of our contemporary players actually sit down the night before and visualize where they are going to hit every shot. Not that they are going to try to be perfect the next day but they are trying to have a good plan to play the course. They are trying to see as much about the course and get comfortable with what they see as much as they can so that they will feel more familiar the next day. Visualization is a performance enhancer, use it.