Thanks Richard, will check it out.
Brister's book on shotgunning was one of the most influential for me on the general topic, though less about the art of shooting.
More recently I read Currie's book on shotgun fitting...
I suspect like you, I mainly learned by shooting. Over time, I became a better than average live bird shooter, though a long way from being a good shot - mainly due to inconsistency at times. But with thousands of rounds, I'd figured out the cues... if I got a bruise in a certain spot or if my cheek wasn't a little sore after a full day, I'd know why I wasn't hitting consistently that day.
Then a close friend was fitted for a gun and got deep into the art and science, and recommended this book - and I realized a major contributor was gun fit, and started to understand the interactions between fit, recoil, and point of aim. Just adding 3/4" to length of pull made a major difference to how my guns shoulder and fit and as a result, immediate improvement in mounting/shooting consistency and major felt recoil reduction. While I'd still benefit from a real fitting and modified stock, it's all but eliminated cheek slap.
I also learned about the impact of eye dominance, and how that is so much more than simply right or left. Though I'm technically right eye dominant, in reality that dominance is very centralized, just barely to the right of the bridge of my nose. A properly fit gun would likely help in a big way, but as I'm not likely to make that investment, understanding this has helped me get over a desire to try to shoot with both eyes open as it is just physically impossible with a stock gun given my condition.