My pulled pork- so if I’m being lazy I use a bottle of bbq sauce, if not, mix 3x big teaspoon mustard, 6x dessert spoons ketchup, honey(usually a big squeeze, guessing I use about 2 spoonfuls?) or maple syrup, cumin, smoked paprika, Worcestershire sauce, sometimes a bit of veg stock cube, and rub over pork, saving a bit to go on the bottom of the slow cooker. (If going lazy option, shove some bbq sauce on the bottom of the slow cooker, add pork, dollop more jar/bottle sauce on top, buy fanciest looking bbq sauce!)
put in pork on high for 2 hours then low until dinner, about 6 or 7 hours. I usually add about 1 cup of boiled water in the first 2 hours. Temptation is to add more water - do not unless it’s completely dried out!
take the pork out and pull then put in a different bowl/serving dish, add a couple of spoonfuls of the cooking liquid and then I often mix in some bottle bbq sauce. (Because best will in the world, I never make up extra of my own sauce for this bit).
if you want to be fancy, swap the water for some cider or apple juice.