When you are smoking a piece of meat that takes a long time to finish, your enemy is anything with tomatoes and sugar in it. Both ingredients burn and can ruin the meat you are smoking. I always recommend to use Turbinado sugar when you are making your pork should rub, or any rub recipe for that matter.
3-Tbsp Tony's or comparable cajun seasoning
4-Tbsp Turbinado brown sugar (this type of sugar will burn at a higher temperature than regular brown sugar)
1/4 Tsp Garlic Powder
1/4 Tsp Onion Powder
1/4 Tsp Salt
I usually mix and store all ingredients in an empty seasoning container.
Tips: If you need more, just double the recipe