Teaching pros and sport psychologists encourage the use of routines because they help reduce anxiety. They help focus your attention, and, with practice, routines become habits that will hopefully lower your scores. Your pre-shot routine might involve standing behind the ball and eyeing your target, taking just one practice swing and taking a deep breath. Superstitions have always been prominent among sports people. The believers think they help bring some form of control over uncertainty, and a sport like golf is full of uncertainty.
Superstitions usually begin when someone has a particularly good shot or round.
People believe that a particular object or behavior brought luck and caused them to play well. As the dictionary says, it's a non-scientific, irrational attribution to success or failure. Unfortunately, superstitions can also be detrimental to your game, particularly if you indulge in several. I once worked with a hockey goaltender who had dozens of superstitions that he called routines. The problem was he spent most of the game wondering whether he had all his good luck charms in place, and spent more time worrying about them than watching the puck.