90% of bad shots happen before you even move the club. Getting your set up right takes a little effort but pays off handsomely in straighter shots and lower scores. As the set up is a stationary position, there is no excuse for getting it wrong. Follow the guidelines below and you can look as good as the professionals do at address.
Some people use the left foot as a reference to make sure they have the perfect ball position:
Others say that you should move the ball position depending on the type of shot you want to hit. So you move the ball back to hit it low. You move the ball up to hit it high or hit a fade shot.
Others say you should keep the ball position constant - underneath the left armpit. Then, if you want to hit the ball high, low, right to left or left to right, you change your swing motion rather than the ball position.
If you keep the ball in the same place relative to your left foot, moving your right foot back will create the illusion of the ball being further forward.
Keeping the ball position in the same place will ensure consistency in your set up which is a key to hitting lots of fairways and greens and playing great golf.
You want your arms to hang from your upper body. A good drill to help with this is to get in your golf posture (without a golf club) move your arms outwards and bring them together for a clap in the middle. Clap your hands forcefully together a couple of times and that will shake the tension out of your hands, arms and shoulders.
The key with the set up is to have all things in moderation. Beginning from the ground - have the feet pointed out roughly 20 degrees, not too much, not too little. Have the knees bent, not to much, not too little. Bend from the hips, again not too much nor too little. Have your chin neither too high in the air nor buried into your chest. Finally, your forearms should be neither turned out nor turned in too much.