It took me 2 years to break 80 consistently. 1 year of just messing around, 1 year of playing consistently.
1) Figure out what your natural shot shape is. Do you hit a draw, fade? I draw my driver off the tee so I know I can set up toward the right side of the fairway. If I do miss the fairway, I know where I will miss (right to left draw). Same with my irons.
2) An obvious, don't chunk or thin and shots. These are wasted strokes. A little more in depth, aim for the middle of the green! If you draw or cut the ball 5 or 10 yards, you're still putting. Pick and choose when to go at flags.
3) Have 2 or 3 different chip shots in your bag. I can play a flop where I lay my 60 degree over, I can play a low spinner that bites when I deloft my 60 or 56, or I can play a chip that will run out. Practice different chip shots and know when to use them.
4) Last and most important, BE A GOOD PUTTER. You will use this club more than any club in your bag. Let's say you're a perfect player and you hit every green in regulation, more than half your strokes will be made with a putter if you two putt every hole for par.