You should be able to close your eyes, mount the gun into the zygomatic arch, and that's your perfect mount. Open your eyes. Are they straight down the rib?
I have come to believe this is not entirely true. I can take a gun that fits my hunting style dimensions 1 3/8 to 1 1/2 at the comb and 2 5/8 to 2 3/4 at the heel (or within these relative dimensions) close my eyes mount it a few times and after that it perfectly aligns. I have a Charles Hellis made for a lefty and can do the same. Let me shoot it for a round to warm up and off I go. That is my hunting scenario for I rarely shoot the same gun twice in a season except my Citori that I use for migratory. Something else is going on and I can't figure it out.
