The goal is to lay with your head and neck in a straight position. If on your back, use minimal lift from the pillow. I roll the sides of my pillow up around my ears so my head does not role to the side. My head is just about flat on the mattress. I notice that with head lift, I had more problems.

When I sleep on my side, I bunch my pillow so my neck is straight.

I learned my best position by sleeping in a recliner chair. I would wake up feeling great. My wife said my face was totally relaxed. If I was in a bad position, I would show stress on my face.

There is no magic position. You need to experiment and see if you do better one way or the other. For me, the important part was to avoid head lift and tilt. No chin to the chest sleeping.

When I find the right position, I can fall asleep and wake up 6 hours later in the same position. Those are my best nights.