jminion has the answer, but I wanted to throw my .02 in, keep the change.
This is what I do and everyone who has had my brisket really likes it. I buy a 12-14# packer brisket, it has the point and the flat. I pour some worchest sauce and lite soy sauce over it and apply a very generous amount of my rub to it on all sides. P.S. My smoker is a traeger pellet. I heat up the smoker to temp 220-240* and put it on there with the fat cap up. I'll smoke it until internal temp reaches 160-170*. Then I take it out and put in fat cap down in an alum foil pan(turkey roaster pan) and cover tightly with alum foil. I then take it to 205* and then pull it out and let it sit and rest for about an hour.
After it has sat I cut the point from the flat and slice the flat(with an elec knife) about 3/8" thick. I place the sliced flat in a plastic container and pour the juice from the alum pan over the top. When you reheat it, it will be nice and moist and VERY tender.
After I slice the flat I cut up the point into about 1-1.5" chunks and put it in an alum pan to go back on the smoker. I also cut of any excess fat, mainly the big chunks. I like to really hit the chunks of meat with the rub then smoke it for 4-6 more hours. I call it burnt ends, althought it really isn't "burnt". These chunks have more smoke flavor and have a real good kick from the rub.
My favorite rub is all mostly equal parts of: k.salt, chili pwdr, paprika, blk pepper, garlic pwdr, onion pwder, and a store bought cajun spice(usually put a little more of the cajun spice in). Sometimes some brwn sugar, too. And sometimes some celery salt.
Gotta go, this also helped me as I'm getting ready to smoke a brisket for some friends.
Good luck.