I'm going to suggest that most of this will happen without our conscious intervention, just like walking or reaching for something, we decide where we want to go or what we want to pick up, and most of the muscle instructions come from the brain without our being conscious of them. In breathing there was a time when a deep breath was with the chest out and the gut sucked in, it takes a conscious effort to learn to breath correctly. That is to let the gut extend and allow the chest to remain as it is. I didn't learn that till I was taking Karate classes and the Senseis taught the students how to breath properly. I found the same thing was taught in Yoga. You only need to focus on the proper form and the details will take care of themselves.