I trim most all of the "hard" fat off. A 12 pound brisket probably weighs 10 pounds when I'm done trimming. I take off that nasty yellowish fat on the fat cap and all the thick stuff. I trim excessive fat off the top of the flat. I also never bother to season the bottom (fat cap).
KCBS Member and CBJ #14287
Contest Organizer - Smokin' on Big Creek
Co-Founder and Executive Director
Operation BBQ Relief, Inc. Visit us at Operation BBQ Relief dot org