A dry rub is the best and easy to do. I use salt, black and white pepper, brown sugar, paprika, chili powder, garlic powder, onion powder, cumin, dry mustard and sometimes other stuff. Mix it all together, rub it on the meat liberally, cover with plastic wrap and let it sit in the frig for 24 hours before putting it on the cooker.
I'll do this with a Boston Butt then put it in a glass baking pan with carrots, onions, celery, bell peppers and a Sierra Nevada Pale Ale, seal with aluminum foil and into a 25deg to 300deg oven for 5 to 6 hour. I have also slow cook it without the veg and beer. Once cooled just pull it apart, add the BBQ sauce you like and chow down.