The stance by itself seems pretty simple, but getting it just right has enough factors to actually make it a complex action of the body for many. Most students who come to me for the first time have errors in the way they set up to the ball; and these are usually the root causes for whatever swing issues they have. Don’t overlook spending time practicing your stance in front of a mirror or camera.
Two of the most important measurements to the stance are getting a 30 degree bend at the hips with a fairly straight spine, and getting the arms hang so that you are the right distance from the ball.
The right side of the body must fit neatly lower than the left, in order for the right hand to fit below the left on the grip. By shifting the hips one inch down the wall to the left (right hand golfer), and kicking the right knee in by flexing it and moving it towards the center line one inch, we will gently tilt the spine to the right a few degrees. This will position the right shoulder lower than the left by precisely the width of your middle finger, ring finger and pinky’s width combined….which is around 2-3 inches.
Most people should only be 6″-7″ from butt end of the club to the thighs – the average golfer’s tendency is to reach much too far. It is better to err standing too close.
Most people should have their heels about 12 inches apart on a driver – the average tendency is to stand with feet much too far apart. Err on the narrow side. Bigger framed golfers (say 6’2″+ and over 210 lbs+) may go as wide as 14-15 inches.