Trim excess fat from the brisket
Season the brisket with salt, pepper, and desired spices
Optional: sear the brisket in a hot skillet for 2 to 3 minutes per side
Place sliced onions, garlic, or other aromatics in the bottom of the crock pot
Add a small amount of liquid such as beef broth, water, or barbecue sauce
Place the brisket into the crock pot
Cover and cook on low for 8 to 10 hours
Cook until the brisket is fork-tender
Remove the brisket from the crock pot and let it rest for 15 to 20 minutes
Slice the brisket against the grain
Serve with the cooking liquid or sauce