I always rub mine with yellow mustard then rub with dry seasonings. The mustard helps the rub stick. In my rub I use lots of brown sugar and a little of garlic salt, onion powder, black pepper, paprika. I let it sit in the rub for 12-24 hours. Then, I smoke with hickory and apple mixed at 225 for 14-16 hours, depending on the size of it. I have a spray bottle with 1/4 oil and 3/4 apple cider and spray every hour or so for the first 6-7. This keeps the outside bark moist and takes a little off the smoke. After about 7-8 hours, I wrap the butt in foil and smoke the rest of the way wrapped. I think the meat is more moist that way. Lastly, I make a finishing sauce with 1/2 apple cider and 1/2 apple cider vinegar, brown sugar and mustard powder. I heat the finishing sauce on the stove and simmer for 20 minutes or so. Once the pork is done, I shred it and pour the sauce on it until the meat is flavored but you don't want it drenched. I eat it plain from there. Ive just played with the amounts to what i like and never measure, but thats what i do. Anyway, good luck. Enjoy some beers in the smoke.