It's important to have a hot side and a cool side on your grill. I stack the coals on the hot side, and have one layer of coals for the cool side. Personally, I think it's a sin to use a gas grill. Cook the tri-tip uncovered for five minutes on each side on the hot side. Although it's sort of an unnatural feeling, ignore any flare-ups. The goal here is to sear the meat. Don't pay too much attention to what it looks like; just stick to the time.

Okay, almost done. Once off the grill, put it in a container to catch all of the delicious meat juice, and cover it with loose aluminum foil to rest for fifteen minutes. The resting time is also important for it to continue the cooking process. Some folks put it on a grill to rest because they prefer to keep the seared outside sort of crunchy.