The proper golf swing will help you to play to your potential. Let`s look at the different directions the ball can travel when struck.
Definitions:
When executing a proper golf swing, there are nine different directions the ball can go as shown in the illustration.
Pulling: When the ball starts out left of the intended direction.
Pushing: When the ball starts out right of the intended direction.
When executing a proper golf swing, your forward swing tends to be the mirror of your backswing.
Pulling:
The direction the ball starts out will tend to follow the path of your swing. If the club head is taken back too far outside on the backswing, you will tend to cut across the ball (from outside in) on the forward swing. This will cause a pull shot with the ball starting out to the left.
Check the start of your backswing:
If my hands are approximately 4 inches from my left leg at the beginning of my backswing and pass in front of my right leg about 8 inches away from it, you can see my backswing is moving on an outside path. This will result in pulling the ball or sending it left of the intended direction.
Pushing:
The direction the ball starts out will tend to follow the path of your swing. If the club head is taken back too far inside on the backswing, the foreward swing will tend to be from inside out pushing the ball to the right.
Check your backswing:
If my hands are approximately 4 inches from my left leg at the beginning of my backswing and pass in front of my right leg about 2 inches away from it, you can see my backswing is moving on an inside path. This will result in pushing the ball or sending it right of the intended direction.
Correcting your pull shots or your push shots:
The focus should be on swinging the club on the proper plane which is established when you address the ball. The shoulders initiate the backswing causing the hands to go straight back and up to the top of the backswing. During the downswing, the club comes from inside the target line, to parallel in the impact zone and back inside on the follow through. As the club approaches the impact zone, it should be travelling parallel to the intended target line sending the ball in the desired direction.
Pulling:
Check the start of your backswing:
Pushing:
Check your backswing:
Correcting your pull shots or your push shots: 
