The only advice for smokin Brisket I can give is to keep a "Log" of your attempts and how it comes out, then try to change only one or two things at a time to get the final result the way you want it. This way you have a roadmap to re-create your masterpiece and the results should come out pretty close to the same each and every time.
Other things to know about brisket...
They come several different ways, packer, trimmed, and flat. I usually only deal with a packer... A packer is a whole untrimmed brisket with the point left on, it seems the untrimmed fat helps to keep the brisket from drying out too much.
Brisket will walso reach a plateau, meaning the temp will raise to a certain point then stall.... dont panic, just let it do its thing and it will be fine.
Fat side up or down? I prefer to do mine fat side up for the first four hours, then flip and mop once an hour.
When its ready to be sliced, make sure you only cut across the grain.
my method entails the use of a foil pan for the last couple hours, when its done... drain the juice and refrigerate... then skim the fat off and use the remainder as a finishing sauce to pour over the sliced brisket before serving.
Good luck with it!!