BODY ALIGNMENT
After placing the club head behind the ball, the clubface should be aligned or aimed with the leading edge at right angles to the target.

The feet are then placed parallel to the target line and then the rest of the body, the knees, the hips, arms, shoulders and eyes should be aligned also parallel. 

This body alignment will encourage the swing path to travel along the target line needed to start the ball on line. 

Of all the alignments, the shoulders will have the biggest influence on swing path, so it is especially important to be parallel and left here.

Clubface aligned first, then  the feet, knees, hips, arms, shoulders and eyes should be all parallel to the target line. If any part of the body is aligned to the left it is considered as ‘open’ for a right handed player. Aligned to the right is ‘closed’. Square’ is regarded as parallel. At the top of the backswing the club shaft should be parallel to the target line. Shaft pointing to the left is known as ‘layed off’, to the right ‘across the line’. Finish position should be in balance and with the body facing to the target.

Small variations are acceptable but what needs to be remembered is that you are trying to give yourself the best chance of starting the ball at the target and hitting the ball solidly.

Because we stand to the side of the ball when you hit any golf shot it means that if you are actually aligned parallel to the target line and correctly aligned that your feet will not actually aim towards the target. The target line or ball line is a straight line that goes directly from the ball to the target and theoretically also extends back away from the target. So when you do place your feet in position parallel then they will actually aim a few metres to the left for a right handed player. Vice versa for a left handed player.

The further you stand from the ball the further left your feet alignment will appear. It would be like you are playing a shot from off railroad tracks, the ball is on the outside track and your feet are on the inside track. These two lines will never meet and this alignment concept needs to be understood otherwise you may find yourself misaligning to the right all the time.

Use of training aids such as an Alignment Guide from Perfectstroke can assist in correct aiming of body at address.

After the feet have been placed in position then the rest of the body should be aligned also parallel and left of the target line. So generally you will do a quick check to see that the feet, knees, hips, arms, shoulders and eyes are all at least facing the same way to help you make solid contact and to start the ball on line.

Regardless of the length of club being used you should be trying to setup in this way with the exception of when playing shots around the green there is going to be a tendency to open up the bottom half a little. When you align poorly at address it usually means you will have to compensate for it later.