So this may seem like a lot, but honestly brisket is one of those peculiar things that requires some unexpected ingredients, a lot of which are completely unrelated to seasoning. All of these work together to make a good piece of meat:
Meat Selection: I've found 10-12 lb (pre-trim) are best. Make sure the piece of meat is as even as possible - the point and flat shouldn't be that different in terms of thickness. Further, I like pliable pieces of meat (i.e. when you bend the meat, it takes little effort to get the ends to touch or close to touching point). This is likely more a factor of the evenness of the meat, but if you have an easy piece and it doesn't bend it probably means there is too much fat you can't render. Forget it and find a better piece or opt for something else. Having marbling in the muscular tissue is a plus. Meat selection is the most important part of the process, and everyone downplays it. I think many don't want it to be known that getting a piece of meat with ideal attributes is a huge head start.
The Trim: "soft" fat is good fat and "hard fat" is bad fat - the soft stays and the hard goes. Why? The hard fat won't render and it denies edible parts of meat contact with seasoning. It also slows the cooking process and doesn't really help in terms of moisture and tenderness (the quality of meat and cooking process is more important there). There is a large hard fat vein underneath the deckle, and it is deep too. Cut this out. Fat on the flat end should be creamy white and about a quarter or half inch. If you have a piece of flat that is thin, trim it off and discard. As I said earlier, evenness is very important (same reason why you truss a chicken or turkey when you roast).
Smoker: fire source should be indirect. Depending on humidity, a water pan or added water may be necessary. I live in Houston, so I rarely need extra moisture. In a dry climate or on those rare days, I'll add a bowl of water or add a little water to the bottom of the pit. Brisket should be near the chimney end - I like fat side up since heat rises. If you are closer to the heat source, use fat side down.
Wood: use wood logs, oak or pecan. It shouldn't be too fresh - it needs to age. Ideally you want "clean heat" coming out of the chimney. What does that mean? Means if you see a lot of smoke, that's not good. This meat smokes for a long time, if you are smoking it out like that it may have a bitter or acrid taste upon first bite. Use wood about one year after harvest and try to remove bark and moss. You should see nice delicate heat waves with little wisps of smoke coming from the chimney, not billowing white clouds. It will absorb the flavor, believe me.
Temp: I believe 250-275F to be ideal. Below that takes far too long and you will stall out. Think about it - if you need to bring the internal temp to 200, does it sound like a good idea to smoke at 210 or 220? Too long for my taste. Smoke at higher temps but pay very close attention to your baby.
Seasoning: this really doesn't matter other than don't apply until ready to cook. Salt on its own will draw out moisture, so unless you have a wet or dry brine you are drying the meat out before it is even cooked. I use salt and coarse black pepper and get a great flavor.
The Cook: bring the meat to room temp before you throw it on the fire. Why? Always a good cooking habit for nice even results. Plop it on, and let her go. You can spray with beer or mop with a mop sauce if you want. I do this to prevent burning. After the meat changes color and forms a good bark, wrap it in butcher paper or paper grocery bags and put back on the smoker. I don't like foil because it traps too much moisture, steams the brisket and kills the bark. Butcher Paper allows the meat to breathe (so it isn't sitting in soup) but prevents further formation of bark, which is a winning combo in my book. When is be meat done? When it jiggles and is quite pliable. This is probably in the 200 internal temp range but is usually situation specific. If you tap the point and it looks jiggly, it's probably just right.
Resting: I don't wrap in foil, I don't throw in coolers, etc. I take the wrapped meat out of the smoker and let it sit for about an hour and a half before slicing. Placing into a cooler or wrapping with towels, etc destroys that bark you worked so hard to make - why do that?
Hope this gives you a head start and remember good brisket is trial and error. Do it often and take care and pride in the whole process. It isn't rocket science, but each step is very important.
