For me the key is through developed motor memory of proper alignment based off my line of sight to the intended target.
Forget about instinctive aiming for a moment and just think about any style of aiming when using proper form and alignment. How does a guy(or gal) place their drawing arm elbow when at full draw on a precise place in space that is in direct line with their line of sight to the target when the elbow is behind their line of sight? How is this possible when you are not looking at your elbow?? The answer is developed motor memory. When shooting instinctive, placing your bow hand on a precise place in space that is inline with your line of sight is no different, it's just in front of you vs behind you like the elbow. When you have the developed motor memory to feel the alignment of your bowhand, anchor, elbow, shoulder, etc., keyed off your line of sight to the intended target, you can become very accurate within normal hunting distances. Think of the radius between your bowhand and elbow when everything falls into alignment by natural feel, that radius is longer than the fixed sight radius of most rifles. When you have this down and you have ingrained the flight of the arrow into your brain, drawing and loosing arrows into your marks, without any thought of sighting references, becomes as easy as placing your finger onto the end of your nose with your eyes closed. When you look at a small spot to shoot and you come to full draw, you can feel when you are lined up and are dead on as if a light comes on in your head:) This comes with much repetition of good repeatable form.
A person who never develops a solid foundation in form and alignment, will probably chase their tail in circles trying to find repeatability using instinctive aiming.
Best,
DB