Grab a pair of drumsticks and practice tempo. Once you understand this, bring it to your golf swing.
Before you can add speed, you must first understand rhythm. Learn how to create a tempo that will help you practice.
In baseball, "squashing the bug" helps you drive into the ball. This is the same in generating speed in golf.
Joe's practice swing was something he prescribed to most all of his students. This trained you to move the club in sync with your body and how to keep the weight of the ball in front of you as opposed to falling behind.