These lists are off the top of my head.
Tier 1: No Real Talent
Grip the club properly - in the base of the fingers, with the right number of knuckles showing for your swing. Set up properly - weight over the right part of your feet, arms hanging almost vertically, ball position forward of center. Learn the ball flight laws. You only have to learn them once. Learn that bad shots happen, and don't require a change to what you're doing or attempting to do. Change your grips when they get worn, slick, hard. Get a video camera, alignment sticks, and a few other training aids. You don't have to spend a lot of money here. Use decent clubs. Your muscle back 2-iron is probably not helping you much. Wear sunscreen and sunglasses. Your skin and your eyes are important. Tier 2: Minimal Talent
Grip the club firmly while remaining athletically "loose" with the rest of your body. Tension in the wrong places can be a killer. Loose muscles are fast muscles. Learn what "start line" and curve your ball has on any given shot. You'll be miles ahead of the game when it comes to solving problems with your swing for the rest of your life. Practice effectively. It doesn't matter if you practice for 10 minutes or 10 hours a week, if you can practice effectively, you'll squeeze as much out of that time as you can. Nobody practices perfectly, but 90% effective is better than 30% effective. Nobody hits perfect shots when practicing, either, but you can make changes when practicing properly. Learn the Shades of Grey and your Shot Zones. Play quickly. Play without fear - golf is just a game we play. Tier 3: Some Talent
Learn to putt with a backswing and downswing that are about the same size. If your ball goes too short and you feel you have to make a huge stroke, just swing it faster, but keep the through and backswing lengths the same. Learn to hit a chip shot with some forward shaft lean and without throwing the trail wrist. I'm amazed at how few people can do this, even if they're just hitting a shot onto a range with no real target, solely trying to "do" this motion. Learn how to make partial swings, particularly with wedges. Learn how to have a "B" swing for days when things are not going well. Develop a ball flight — it's okay if it changes as you continue to improve — and apply the bullet point in the section above to play it. I allotted myself 15 minutes to write this post and come up with what I could come up with, and that's it. Please add your own in the comments below.