Play games on the course
Again, you learn to score by being on the course and playing, not by hitting hundreds of balls on the range.
If you can play late in the evening when the course isn't crowded, hit two balls-a kind of best-ball competition against yourself. If you're walking, you won't want to hit one ball 100 yards left and the other 100 yards right, so this will encourage you to be more consistent. Or play two balls on each shot, and then play from where the worse shot lands-that will tell you how inconsistent you are. Or play from where the better ball lands-that will tell you how good you can be. Or miss every green on purpose-that will force you to work on your short game.
Practice smart, not long
Keep your practices short and focused. I learned this from four great coaches in other sports: John Wooden, Bobby Knight, Pat Riley and Bill Walsh. When you do go to the practice range, focus on just a few basics, such as accelerating through impact, contacting the ball on the descent (except with the driver), putting your right elbow in the slot by your side on the downswing, moving your weight to your front foot through impact and finishing in balance. Limit the number of balls you hit on the range. Do your work in focused stints, then leave.