One of my favorite swing drills to do on a hot day is to burst a water balloon with my driver.
This drill teaches you to swing through the ball along the target line. Place a water balloon 2-5 inches ahead of the ball along the target line. If you swing correctly, the water balloon will splash just after contacting the golf ball.
In the illustration below I have fully turned my back to the target with my shoulder under the chin. (picture #1)
To deliver the power in my forward motion, I must simultaneously rotate my left hip over my left heel, thus allowing me to transfer my lower body toward the target. (picture #2)
In picture #3, my right hip swings around toward the target as my arms extend down and out along the target line as the club head contacts the ball and explodes the water balloon.
Notice in my finish, (picture #4) my hands are over my shoulder, my hips have completely turned facing the target and my knees have come together keeping me in complete balance.
Next time you head to the range, prepare a few water balloons to splash through. Not only will it help improve your follow through, you will have fun and stay cool.