Purchase: I purchase only un-enhanced butts. I have had many a bad outing wasting my time, effort, and monies not including reputation trying to make an enhanced piece of **** taste worth a darn. Usually they come 2 to a cryovac pouch.
Inject: About an hour before putting on the smoker. Sooner, like overnight, will concentrate the sodium and allow the whole thing to become "hammy". I use my own modified version of Chris Lilly's injection, with a LOT less salt than his calls for.
Rub: Just before injecting. I use my own, but it's very similar to Plowboy's Yardbird, just less sodium.
On the smoker: On my smoker I use hickory; that smoke flavor works for me and with my rubs and injections. Yours may vary. I leave it on smoke for 4.5 hours.
Foil: I foil for color and to govern the amount of smokiness we have in/on the meat. I use ONLY Heavy Duty foil, wrapped TIGHT.
On the smoker: FYI: I cook in the 260 temperature range. If it dips to 240, no biggie. If it spikes to 280, again, no biggie. Total cook time for large 8.5-10.0# butts is usually around that 9.5 hour mark.
Off the smoker: rest for 2 hours or more.
Pull: I pull then into chunks. I do NOT mince them into oblivion, nor shred them beyond belief, nor pull them into tiny thin pieces. These destroy the product I've worked to hard to create. Chunks, roughly the size of my thumb. They hold moisture and their flavor much better.
Eat: If you need a description here, then you're on the wrong forum.