24 hours prior to grilling, rub the tri tip with the linked seasoning and put in a plastic zip lock bag and back in the fridge.
amazonAmazon.com : Pappy's Choice Seasonings - Original. Perfect for bbq and smoked brisket, steak, beef, chicken, fajita, hogs, rib, seafood, bagel, popcorn, jerk, pizza and more. : Gourmet Rubs : Grocery & Gourmet Food
https://www.amazon.com/dp/B002ODE1PQ/ref=nosim?tag=cougarboard07-20[https://www.amazon.com/Pappys-Choice-Seasoning-Professional-Pack/dp/B002ODE1PQ/]
Remove meat from the fridge ~1hour before cooking.
For charcoal grills:
After removing meat from fridge, Prepare a chimney full of charcoal and let it burn in the chimney until all briquettes are white.
Put the charcoal on one side of the grill.
Put the meat, fat side down on the cold side of the grill, cover and wait until desired internal temperature is reached. Ideally you would monitor the temp of the grill and keep it no higher than 300 degrees, but tri tip is very forgiving and even if it is cooked quickly at a higher temperature, it will still turn out good, and it can be difficult to keep a charcoal grill at a constant low temp. Cooking it slower will produce noticeably better results. If you are in a hurry you can sear both sides ~3 minutes each on the hot side of the grill before moving it to the cold side to cook it faster.
On my weber charcoal grill I can do two tri tips at once.