I have been grilling them for years and have not "smoked" one yet. I usually use the garlic, black pepper and sea salt on mine. I also grill with direct heat to get the grill marks and the crispy outside then move off to indirect heat and toss in a foil packet of hickory chips and close the lid for 15 minutes to get some smoke
I agree with what they said, In comment to Hilbilly's post, I THINK the santa mariea style/rub has some rosemarry,sage?,and basil? in it.
You wont go wrong with any of the above listed, I have done many with SnP,and garlic,and onion powder. I'm not huge fan of rosemarry,but many do.
Lots good advice above,try and see what works for you.
I recently did a reverse sear on a tri tip and I absolutely can't wait to do it again. It was all gone just minutes after slicing. The first one I tried I left in the smoker a bit too long and it was close to well done which I don't like. The last one was still a lil more done than I would have preferred but it did still have some pink in the middle and it was very, very moist!