I use a rub recipe that I got from Alton Brown years ago. It’s similar to this one:
https://www.cookingchanneltv.com/recipes/alton-brown/barbecue-st-louis-pork-ribs-2047251

Put the rub on the day before and refrigerate overnight. I like to cut the butt up into smaller portions for more bark. I put them in my smoker or on a Weber kettle grill with the coals off to one side. I add wood chips for smoke. After getting a good bark (~4 hours) I move it to a slow cooker or instant pot. I slow cook it until it pulls apart with forks (~2 hours). I’ve tried just the smoker but it drys it out too much but is still good. When I’m somewhere without a grill or smoker I’ve broiled the meat in an oven for somewhat of a bark but less smoke flavor or a gas grill.

I actually smoked one today and we had it for dinner. It was delicious.