For me, focus is not a verb, aka action,... it's a state of mind.If you are properly aligned with the 'Magic T' as I call it, the follow through will take care of itself, as will the release, windage, and bow arm.
“Burn a hole in it” is what Hill said. I personally like the phrase “ aim small, hit small “. To make my point I bought those little red dots and cut them to fit the eyeball of the prairie chicken target. Trying to help (not teach) seniors that are new to archery keep their arrows in the target butt. Unfortunately a few can’t see the dot at 20 yards. “Imagine “ that dot in the kill, it helps me. But as I tire my focus will shift, worst since I hit the 70’s in age.