here are a few suggestions;
1- leave your driver at home and use a 3 wood on the tee
2- practice long putts. make your goal to try to 2 putt every green. Most amateur golfers usually come up short when they do manage to hit the green and end up with a long first putt. if you can 2 putt every green instead of 3 putting you'll shave 18 strokes off your game right away.
3- practice chipping. Like coming up short on the green, coming up short on your approach...