Learning generally boils down to "Repetition or the avoidance of pain", some people learn by doing, some by watching and some just have to pee on the electric fence.
Whether you think that you can, or that you can't, you are usually right. Henry Ford
Most of the butts I get here are in the 10-12lb range I cook around 225-275 depending on how busy I get and let it climb and fall cook time takes around 10 hrs and the last 4-5 hrs is triple wrapped in foil with apple juice. This method hasn't let me down. I will spray them every hr with apple juice and cider vinegar.