The easiest way to insure a bad golf shot is to stand over the ball and say "Ok, keep your head down, bend the knees, keep the left arm straight, and don’t forget to swing slow."  Our brains are not fast enough to process all that information in the 1.5 seconds it takes to swing a golf club.  Trying to think of so many things will only lead to an unnatural and jerky swing - the leading cause of bad contact with the golf ball and poor results.

Sound swing mechanics come from creating proper "muscle memory" on the practice range.  When you’re on the golf course, focus on your target and one swing key such as "turn to the target" or "slow and smooth."  This will allow you to take a natural, more relaxed swing.