Preheat your smoker to the desired temperature of 225°F as per your smokers manufacturers instructions. Ensure the tri tip is not in the refrigerator and has come to room temperature.
Trim your tri-tip of any silverskin or membrane. This is not a must, however, you will be left with a more tender result. Silverskin and membrane do not render down during the cook so it leaves a nasty texture in your mouth.
Combine your dry rub ingredients in a bowl. Mix thoroughly with your hands. Place tri tip inside a baking dish and coat well with the olive oil. Then cover with the rub. Be sure to give it a good rub to thoroughly coat all sides for best flavor. If you have a digital thermometer place it inside the tri-tip so the end of the probe in at the centre.
Place tri tip tray in your smoker or grill and cover. You are wanting to smoke until the thermometer reads an internal temperature of 135 degrees F for medium rare at the centre. This should take around 60 - 70 minutes.
Once the tri-tip has reached temperature move onto a wire cooling rack (with a foil pan below for drippings), cover with foil and rest for 20 minutes until the meat has rested and it has cooled to your desired temperature.
Once you have let the meat rest, cut 1/4 inch slices against the grain and serve. My personal favourite is to make sandwiches with freshly baked bread and lots of crisp salad. Delicious!