Remove the tri tip from the oven, cover with foil, and allow it to sit for 15 minutes before cutting in. The internal temperature will continue to rise during this time.
While the meat is resting heat up your tortillas. I like to add a little bit of oil or butter to a skillet, heat it, then let the flour tortillas heat up and brown a little.
After 10 minutes of resting, cut the trip into pieces.