If you prefer a juicy tri-tip roast from the charcoal grill and don't want to marinade over night, try using your favorite seasoned salt, and the indirect method on your grill. If you like this technique, you will find it an easy way to entertain a large number of guests, as cryo bags of tri-tips roasts are typically available through your wholesale club with 6-7 roasts in each. I have shamelessly stolen this technique from my brother-in-law, a professor of animal science, who, with my sister, have served this to thousands of guests.