This drill with the exercise balls can help increase your rotation and help you hit the ball a lot farther. All you need is a ball and a wall.
Take the ball, put it against the wall, then get in your golf posture. The idea is to roll the ball behind you down the wall with your rotation. You should also feel like your lead heel is coming off the ground a little bit as you get more rotation. The bigger the rotation, the more room and more time you have to accelerate that club.
Now on the way through, try to move the ball to your right. Gear the ball back down the wall into your impact position. This exercise will help you get the ball out farther.