One of the fastest ways to improve your scoring is to think about each shot in the same way a professional does.
Improving your shot selection from the tee and to the green will lead to huge improvements in scoring – without hitting any balls on the range.
A hole measuring more than 250 yards does not automatically require driver from the tee, assess the hole before choosing a club. Is there a hazard at your average driving distance? Can you find the green with your second shot while taking that trouble out of play?
Apply the same process as above on your approach shots. Here I have a shot to a flag protected by a bunker and a steep run off area. Rather than risking a bunker shot or a tricky up-and-down from the short side, play to the centre of the green in the knowledge that a less than perfect shot leaves you with a putt for birdie rather than a difficult up-and-down.
A yardage book, range finder and knowing how far you hit each club are important tools in making the right decision for each shot.