Now, Brenda says she has her favourite recipes but couldn't be persuaded to part with them (that national treasure thing, I think), so I did some research and came up with some creditable versions I think you'll enjoy experimenting with.
The Rubs
This makes enough rub for 20 or so briskets but don't worry, it stores well.
1 cup sugar
1 cup salt
1/2 cup chili powder
1/4 cup garlic powder
1/2 cup black pepper
1/4 cup dried thyme (optional)
Combine all ingredients and store in an air tight container. When you're ready to cook, rub about 3 tablespoons into your brisket. I actually liked this one with and without the thyme, but you decide.
Okay. So you get the idea. The rub is seasonings that are combined and rubbed into the meat prior to its slow cooking process. In my research I found that rubs can be quite complicated with many ingredients and very simple with just a few essential ingredients. I also saw a recipe that called for the brisket to be coated in prepared mustard and the liquid replaced with beer. Creativity seems to be the key.