It's almost impossible to overestimate the importance of the proper set-up to the quality of your shots. Jack Nicklaus asserts that if you set up correctly, there's a good chance you'll hit a reasonable shot, even if you make a mediocre swing. If you set up poorly, he adds, "you’ll hit a lousy shot even if you make the greatest swing in the world."
Align your body parallel to the target line. Your hips, knees and feet should be positioned along the same line -- parallel to the target line.
Position your feet to the appropriate width. The general rule is to spread your feet to shoulder width for mid-iron shots. Your stance should be about 2 inches wider when you use longer clubs, including your driver, fairway woods and hybrids, and about 2 inches narrower for short irons. Your back foot should be square to the target and your front foot rotates 3 inches to the left so your toe is pointing more toward the target.
Establish the correct ball position. To hit your short irons and wedges, the ball should be in the middle of your stance. With longer irons, the ball should be slightly closer to your front foot. The ball should be a bit closer to your front foot as the clubs get longer. The ball should be positioned parallel to your left heel when you hit your driver.
Distribute your weight evenly between your feet. Your weight should be centered on the balls or midpoints of your feet. Avoid putting your weight on either your toes or your heels, as doing so will make your swing unstable.
Stand close enough to the ball that you do not have to reach for it. Tom Watson says many amateurs stand too far from the ball, causing stiffness in their shoulders and often producing an outside-in swing, which in turn usually results in a slice. Watson told Golf Digest, "I tend to agree with Byron Nelson and Johnny Miller, who've said you can't stand too close to (the ball.)"
Place the club head directly behind the ball with the club face aligned to the target.