Undoubtedly fundamentals are important in golf. Grip, posture, alignment and ball position are all important prior to starting the swing. But what about the fundamental action that occurs between the start and end of the swing?
The fundamental action I am talking about is the free and fast swinging of the arms. It is interesting to me how much instruction today emphasizes the legs, hips, shoulders, etc. with very little mention given to the arms.
After 30 years of teaching I can say with confidence that 8 out of 10 golfers have inadequate arm, hand and wrists motion in their golf swing. This is partly the result of their being told golf is a “big muscle game”, in which they are taught to use their legs and hips before they’re taught to use their arms and hands to square the clubface.
Regardless of your “method” the arms must swing freely so you are able to apply the clubhead to the ball at maximum speed. When a player lacks this free swinging action they are forced to apply themselves to the ball - the swinging of the arms is replaced with a heaving of the shoulders.
If your shots lack distance or you have poor balance you should focus on one thought at the top of your backswing: Use your arms to swing the clubhead down and through the ball.
It is true a good player's downswing is started from the ground up. But if a player lacks a free arm swing to think of starting the downswing with the legs or hips will lead to an early unwinding of the upper body resulting in a weak glancing blow.
The best drill I have found to promote the feel of a good arm swing is make swings with your feet together. From this position you quickly learn to swing the club down with your arms, and any overuse of the upper body will lead to a loss of balance. Tee the ball up slightly, and using a 6 iron begin making half swings. Relax your grip pressure so you can feel the weight of the clubhead and swing at about 80 %. You'll be surprised how solid and far you can hit the ball with so little effort.
In my opinion too much emphasis in teaching today is based on what the tour players do. I’m not saying what they do is incorrect, but the weekend player lacks the ability, physical gifts and years of training to play golf the way they do. Acclaimed teacher Harvey Penick said it this way, “First you teach a golfer to hook the ball by using his arms and hands correctly. Then you teach him how to take the hook away by using his body and legs properly.”