I like a dry rub of black pepper and paprika. The paprika is from peppers harvested from our garden.
Last year, I put up about a quart of ground paprika powder. I grind it with a small coffee grinder. It’s not as fine as grocery store product but has a pretty good “snap.”
Well, that's a start.
Seriously, a good rub will draw moisture to the surface in order to make a "bark" and will also penetrate to tenderize.
I use paprika and black pepper and salt.
And a few other things...in classified quantities.
The exact nature of which, if disclosed, would result in my having to kill those to which it was disclosed.
Briskets are extremely touchy.
The majority of mine are simply thin-sliced and eaten on freshly baked sourdough bread.
The one's I screw up...become chopped BBQ for hamburger buns, which I immediately disavow any knowledge of.