I would start with a good piece of meat, USDA Choice or above. It does make a difference. Also, don't go crazy with trimming off too much fat, Leave a 1/8 to 1/4 layer on the bottom as an insulator from the heat, and don't dig too deeply into where the point and flat meet, just trim off the big pieces. Trim with a sharp knife when the meat is cold, the fat comes off easier and there's less of chance you'll loose a finger tip. Under 14-16lbs I don't separate the point from the flat. Sure, the far end of the flat may dry out a little, but you've got 10+ pounds of meat anyway.
Rub is personal preference, I use Dalmation rub (50/50 course ground pepper and sea salt) and leave it on for 24hrs so the salt penetrates. My smoker is a size large Green Egg with the Conveggtor inside which is key to keeping the heat indirect. Lump charcoal only, but I throw some apple or cherry hunks on. I also use a drip pan filled with hot water directly under the meat. It serves 3 purposes; keeps the meat from drying out, acts as a heat sink to prevent temperature spikes, and to catch drippings that I later use in my sauce.
Smoke time is around 18hrs, plus/minus. I keep temps as close to 225F as I can. I have a Thermoworks Smoke X4, I put a probe in the point and one in the thickest part of the flat. I usually start the smoke around 8-9pm, go to sleep, then wake up around 8am and foil wrap it (Texas Crutch). The wrapping is controversial, but in my opinion its already picked up plenty of smoke over the past 12hrs (I don't like it over smokey), it helps me get through the stall faster, and I still have good bark. I take it off between 198-200F, depending on how it jiggles, then stick it in a cheap cooler (while still tightly wrapped in foil) wrapped in towels until the internal temp goes down to around 130-140ish. This step is important because carryover cooking happens, it reabsorbs some juices, and If you try to slice it when its too hot it will fall apart and shred.
If this sounds complicated, its not. The only way to really fuck up a brisket is to overcook it, let the heat get too high or keep in on until the internal temp gets over 204. You'll do fine as long as you keep an eye on the temps. Post some pics when you're done.