Smoked tri tip is really good. Salt, cracked pepper, and granulated garlic, smoked to an internal 145 if you like more rare. My family tends to like it more well done, so I take it to an internal 160, pull, and let rest for at least 15 minutes.
I also like to cook Santa Maria style.
Salt, cracked pepper, granulated garlic, and dried rosemary
baste through cook using red wine vinegar/garlic infused olive oil (or just plain olive oil) 50/50 equal parts of each (I usually use 1 cup of each)
Cooking on a hot grill, best if using red oak firewood, grill, turning and basting regularly until internal of 145 to 160 depending on preference.