The best way to prevent any food from burning on the grill is to have proper control over the heat. For charcoal grills, it’s important to create hot and cool zones by adjusting the charcoal to different levels once heated. The higher the charcoal the hotter that section will be. For gas grills adjusting the knob to reduce the flame will lower the temperature. In addition to proper heat control, some essential items are great for mitigating the temp, a simple spray bottle filled with water is a great way to calm some of the flames down if you are getting flare-ups. Try and use oil and fats sparingly as they act as fuel for the fire. Additionally, par cooking potatoes can mitigate the amount of time the potatoes are on the grill which can lessen the chances of the outside of the potatoes burning before the inside cooks. Lastly, keep some aluminum foil handy as foil can be used to shield the potatoes from the flames once they are done cooking. This can also be accomplished by positioning the potatoes on an elevated rack on your grill. With potatoes, it’s best to start out low and slow, and then crank the temp to crisp up the exterior once the interior is fully cooked.