My favorite tri-tip roast rub consists of 4 ingredients and makes for a decently well-seasoned and tasty meal. I start with a tri-tip roast that is a few pounds in size. I think add it to a zip-lock baggie with a few tablespoons of olive oil to help things stick. I then add equal parts of garlic powder, freshly ground black pepper and lawry's seasoning salt. The combination of these three items seems to make for a deliciously seasoned roast. You can add as much or as little as you like but my family prefers it semi-caked on and done medium-rare!