As a high scorer myself I have found several things that have really improved my game over the last two years.
1 - Read either (or both) "Golf is Not a Game of Perfect" by Dr. Bob Rotella and "Zen Golf" by Dr. Joe Parent. These two books really improved my game by showing me how important the mental game is and ways to help keep my head in the game.
2 - Short game - It is amazing how many strokes you can cut off by being able to get it on the green and two putting.
3 - Break down a hole to make it playable to the club you can hit with confidence - Example, I hit 6I well enough to get me into striking distance (150 yards). On a 395 yard par 4 hole that would be two 6 irons shots, a comfortable distance short iron shot (see tip above), and a two putt. That is a bogey. If you score 9 "5"s in 9 holes that is a score of 45. This thinking even gives you a cushion of 4 strokes to still hit 49. Double the score for 18 holes and you get a score of 90-98.
4 - Sometimes a hybrid or 3 wood is better off the tee - Sometimes I find that when I am having driver issues I go to my super hybrid off the tee. In most cases I am only losing 30-50 yards distance but I know I can hit it in play and have a good lie for a 2nd shot. This year I plan to add a 3 wood to my bag for this purpose as well.
I am no expert but these things have made a huge difference in my game, especially number 1 and number 4.