Preheat the smoker to 250°F using oak or another hardwood that pairs well with brisket.
Make the rub by combining all ingredients in a shaker if you’re using the our brisket rub recipe.
Trim and season the tri-tip by removing silverskin and excess fat, leaving about a 1/8 to 1/4 inch fat cap. Square the edges and note the grain direction so you can slice against it later. Lightly coat the meat with Worcestershire sauce, oil, or mustard, then season generously on all sides with the rub.
Smoke the tri-tip. After the first hour, spritz lightly with beef broth every 45 to 60 minutes until the bark is dark and firm and the internal temperature reaches 165 to 175°F. This usually takes about 4 to 5 hours.
Wrap the tri-tip tightly in butcher paper or foil once the bark is set and doesn’t rub off easily. Add 1 tablespoon of unsalted butter or beef tallow on top before sealing.
Continue cooking for another 1-2 hours until the internal temperature reaches 203 to 205°F and a probe slides in with little resistance.
Rest the tri-tip while still wrapped, then wrap it in an old towel and place it in a cooler for at least 30 minutes, ideally 1 to 2 hours.
Slice the tri-tip by locating where the grain changes direction, separating there, and cutting each section across the grain into thin slices.
Serve immediately with your favorite BBQ sides like mac and cheese or potato salad.