Practice Drills
The Swoosh Drill
A great drill to practice at home or the golf course is the Swoosh Drill. Most golfers release the club too early causing a loss in power. This drill helps train you how to properly release the club while maintaining and increasing your lag.
To perform this drill you can either use a shaft with no clubhead attached, or simply turn your driver upside down and grip the shaft just below the clubhead. Set up as if you were going to hit a real shot and make a swing at full speed. Since the shaft is so light, you will notice that your swing will create a swoosh type sound. This sound is made at the fastest part of the swing. In order to maximize your swing, you need to hear that swoosh sound at and after your impact point with the ball. Most golfers will hear the swoosh before impact which means they are releasing the club too soon and aren't creating any lag. Keep making full speed swings until you start to hear the swoosh at and after impact position. A helpful tip is to swing as easy as possible on the downswing until you have passed the impact position then try and accelerate. This will feel strange at first but it will teach you to maintain your lag as long as possible. The further you can delay the swoosh sound, the more lag you are creating and the faster your swing will get. Once you have mastered this, apply the same swing when hitting the driver.
In the picture above, notice the two separate sections, "Red and Green". If you hear the swoosh in the Red section, you are releasing the club too early and exerting too much effort before impact. You want to hear the swoosh when your club has made it into the Green section.