A fast accurate golf swing relies heavily on correct bio-mechanics and positioning of the golf club and your body, as much as it is important to understand the fundamentals and mechanics of the swing, over analyzing it can really just work against you.
A good golf swing will eventually become all about tempo and rhythm and not bio-mechanics and strength, if you feel you have to force any part of your swing then you probably need to make adjustments somewhere, because extra force does not necessarily translate to better results.
A good golf swing should produce a good result and feel almost effortless.
Relax for Results
Constantly thinking about each part of your swing each time you go to hit the ball, causes tension in one or more area in the over all chain reaction that you set in motion to hit a ball, from the winding up of the coil (setting the backswing), to the uncoiling of the spring (the strike and follow through), this needs to be smooth and flow rather than stiff and rigid, learning how to relax in this process is the key to a more effortless swing.
The Perfect Set Up.
There are only 3 times you should have to think to yourself through a golf shot. The first one is the set-up and this is what dictates the rest of the motion.
Start with your grip, make sure it feels around a 2 out of 10 for strength, your arms should literally hang from your shoulders with little to no tension what so ever, and your shoulders should be loose and relaxed.
Having a relaxed start lets the rest of your body dictate the speed of the swing and not the arms, this should slow your swing down but open the possibilities to getting more power into your swing, which eventually also gives you speed, not the other way around.
A petite female golfer who uses their body to produce power and speed in the swing, will be able to drive longer and more accurately than a solid male that tries to use the strength in their arms and not the whole body to hit the ball.
Secret to a Good Swing
Spending time on the driving range concentrating on learning to relax with your shots rather than hitting as far as you can is one secret to a better technique, once you learn to relax you will most likely notice longer shots coming more effortlessly, and then you can start to adjust the level of the hit with your body and not the strength in your arms to make your drives even further and more accurate on a consistent basis.