Fire up your smoker to cook at 225 F. Use a lighter wood, such as hickory, apple or cherry.
Trim any large pieces of fat off the pork. You don't have to be real picky about it, just get any large chunks.
Combine the injection ingredients. Inject half of the liquid into the pork shoulder. Reserve the remaining injection liquid.
Combine the rub ingredients and rub enough onto the outside of pork shoulder to season it well. You'll have leftover rub.
Transfer the shoulder to the smoker and smoke until it reaches 160 F, about 7 hours. Spritz the pork with the reserved injection liquid every 30 minutes.
Wrap the pork tightly in foil and continue smoking until it reaches 195-200 F, another 2-3 hours.
Remove from the smoker, wrap tightly in foil and let rest 30 minutes or up to 2 hours before chopping or shredding.