Posture is important in golf and you should always bend from the hips instead of the knees. Keep your whole body relaxed though - do not lock the knees out completely. Your feet should be square and set about a shoulders' width apart. Your feet, knees, hips and shoulders should all be in line and parallel to the flight line of the ball. Your left foot can open out a little as this will help you when it comes to following the swing through.
 
Your weight should be balanced between the balls of your feet and your heels and you can 'waggle' a little on your feet at this point to make sure that you are well balanced and relaxed. It is important that there is no tension in your body - the only place that may feel taught at address is the inside of your back leg.

You should feel firmly planted on the ground to give yourself a solid platform for your swing. If you feel a little unstable, then shift your centre of gravity down and back a little (remembering not to bend the knees too much) until you feel comfortable and not off-balance. Your hands, depending slightly on the club you are using, should be around a hands' width away from the body.

The swing is all about rotation and by practising this movement and by making sure you can do it in a comfortable and relaxed way will hugely improve your chances on the course. You can get a feel for the correct movement by holding the club horizontally across your back while in the correct starting posture and allowing your entire body to rotate from side to side.

Let the movement begin with the hips, making sure every part of your body follows the movement through simultaneously and naturally. When you're ready to swing with the club in your hand remember this movement, beginning with the hips, because it will prevent you from getting too caught up in what your hands and arms are doing. The momentum of the swing should be enough to allow everything else to follow without you focussing too much on specific parts of your body.

A good way to begin the backswing is to imagine your body was already moving and you are simply continuing that momentum upwards into the first part of the swing. This will give you a much more natural movement. During this part of the swing the knees should remain slightly bent and relaxed, but completely stationary.

The head should also remain still, focussed downwards on the ball but with your chin slightly lifted. Your shoulders will turn as you swing upwards until they are at a right angle to your spine, with your back facing the target.

After the momentary pause at the top, you begin the downswing. Your weight should shift forward, pulling your body around as your arms unwind, ultimately ending with your belt buckle facing the target. Your knees should not have moved - only upon impact does your right knee straighten out as the momentum brings the club back over your head.

One important thing to remember is not to force your head to stay down - as your club hits the ball it's okay to look up as your whole body is pulled through the swing. The whole movement should feel as natural as the way your arms swing by your side as you walk - carried by momentum, not the tensing of muscles.