So, the basic fundamental principle for accuracy is to shoot the 20 yd shot, with the same exact form, exact same technique every time you step up to the line.

1) balanced weight distribution (even pressure on the left and right foot)

2) wear a shoe with a slight heel (cowboy boots, hiking boots, running shoes) this will help keep slightly more weight on the balls of your feet, and less weight on the heels of your feet.

3) Don't slouch front to back. Don't lean sideways left or right. Easier to consistently stand up straight. You can close your eyes and naturally stand up straight (adams apple on the neck lined up with the belly button) repeatedly, time and again.

4) Pull into the wall the with the same amount of pressure for each shot.
If you have dark color strings, have a friend mark your cables with a dab of white paint on both of your cables when the bow is at full draw. Adjust your release to fire, just a smidgen past this point (pulling into the wall).

5) Use a bow sling, and learn how to shoot with a completely relaxed bow hand. Think of the bow hand as a sofa cushion. When the bow fires, the bow should fall out of your hand. The sling prevents the bow from crashing into the floor. Consistency is the key here. You can consistently completely relax the bowhand. A completely relaxed bowhand will react against the bow grip the same way every time, just like the Spot Hogg Shooting machine grip holder.

6) Adjust the bow arm elbow bend, the bow AMO draw length setting, the length of the d-loop and the release neck length (stick to one release), such that the tip of the release elbow is directly behind the arrow, when you have a picture of yourself taken at full draw, where the camera person is taking an overhead looking down picture. See picture below.

7) Relax the release arm muscles. Learn how to get the release to fire using your larger back muscles.