A good set-up starts with good posture. Stand tall, with your feet shoulder width apart, and your hands on your hips. Bend forward approximately thirty degrees from your hip sockets (not your waist). This will keep your spine more in a straight line. The flatter your back is the easier it will be to turn. Lean forward until your heels start to come off the ground. Now, slightly bend your knees. Your weight should be on the balls of your feet. From this position let your arms hang down relaxed, they should hang under your shoulders. Clap your palms together and hold that position. Now that you have a good set-up, lower your right arm (for right-handed players) and take your grip. You are done.
Hold the club so that the butt end of the club is pointing at the seam of your zipper. We measure the loft of the clubface when the shaft is at ninety degrees. If the shaft moves forward, the clubface will open; when you square the clubface to the target line the club will have less loft. If the shaft moves back (away from the target) the face will close; when we square it to the target line the face will have more loft.
The ball position comes last. Let the ball position be dictated by the club manufacturer. With a wood, the face of the club is ahead of the shaft so the ball is already ahead in your stance. With a mid-iron, the shaft tends to go right down to the leading edge, so the ball would be in the middle of your stance. With the short irons, the face is behind the shaft so the ball would already be in the back of your stance. The ball position moves only a slight amount in the set-up. If the ball does move an extreme amount it changes its location in relation to the arc of the swing.
Move your feet until you have the ball in the center of the clubface (concentrating not to lose the relationship between you and the club). Placing the club behind the ball and then setting up to the club is not an incorrect way of setting up, however, there is no guarantee that it will be done correctly. The set-up is one of the absolutes or fundamentals that promotes success. If you set-up to the club as was explained above there is little chance of being off.