Placebo's post pretty much nailed it.
Here's how I do it:
-The night before, I rub it with mustard, then my rub.
- Which rub is a matter of taste. If you're using rub with your Spare Ribs (and like it), then you have a good rub for shoulder.
-I'll pull the shoulder out of the fridge for an hour if I have time. Otherwise I'll keep it out while I fire up the ECB.
-I stick it on the ECB for at least 2 hours without messing with it.
-After 2-2.5 hours, I'll start checking on the ECB once an hour. As I do that, I'll also spritz the shoulder with apple juice. I'll use this time to check the temp when I'm farther into it.
-I typically only use smoke wood (apple & cherry) for the first 5 hours. After that, it's all charcoal.
-Around 160-170, I typically take it off the ECB, wrap it double in foil, spritz it with apple juice, then stick it in the oven @ 250. Technically, you can leave it on the smoker, but like many others, I pull it to conserve on fuel.
-At ~200 (actually, 195-205 depends on how my patience holds) I take it out of the oven, wrap it foil and all in blankets, then stick it in a cooler for an hour or so.
-After that, I'll take it out and pull it. I typically start with forks and end up just using my hands. I just find it too hot to handle right away. :)
-After pulling, I'll lightly sauce it and mix. From there serve it right away or stick it in the fridge for the next day.
For a 9# butt, it would take me around 18 hours for the whole process, which is admittedly a bit long. A combination of ECB limitations and operator error are to blame. The key is to trust what the themometer says, not the clock. I always try to smoke butts a day before an event to make sure I finish and I am rested and sociable the next day.