First, be sure to grip your club with your front hand (usually at the left hand, for right-handed players) so the thumb lies along the body of the club. Make sure the line between your thumb and index finger points towards your right eye. Then wrap your backhand (right hand) over the left so your left thumb fits directly into the cup of your right palm.
Second, spend some time fine-tuning your stance by pointing your knees slightly inside. Point your right foot straight ahead and the left one slightly to the left. Again, this is for right-handed golfers. Do it in reverse if you're left-handed.
Third, bring in your elbows and your arms as close to your body as you can get them. When you are in your stance, your right elbow should be pointing directly at your right hip, with the left elbow pointing directly at your left hip.
Fourth, begin the backswing with your hands, and then follow it through with your arms and your shoulders.
Fifth, during the backswing rotate your hips back towards the ball. If your swing does not begin with your hips, it will lack power. Your left wrist bone should point at the ball at the moment when the club makes contact with the ball.
Most importantly, you must practice as much is possible if you truly want to fix your golf swing.
Fixing your golf swing takes patience and time. It is not something that you can learn from a book, or even an informative and well-written article. To truly fix your golf swing, you must practice swinging out on the golf course while keeping these tips in mind.
Another good way to fix your golf swing is observing the swing of others. If you can watch yourself or others in slow motion on videotape, that can be very helpful in identifying particular aspects of the swing that may need work.
It can be very frustrating to try to fix your golf swing. You may not have the power that you want to send the ball as far as you would like to, or in the direction you believe it should go, but that will come with time.
Do not obsess over your golf swing as many people do. Remember that golf is supposed to be enjoyable, and should bring you some relief from the stress of your daily life. Every time you golf, focus on fixing the fundamentals of your swing and the speed, power and accuracy will follow.