Single serving or pre-packaged portions to minimize the number of people who come in contact with the food. Use baggies or plastic wrap to store the food. Processed foods such as lunch meats and hotdogs spoil quickly, so use caution with them. Watch the temperature of casseroles, especially those that contain egg, milk products, or meat in them because they tend to spoil quickly. Buy reasonable quantities.
Ground meat is done when it is brown or gray inside.
Poultry is ready when the juices run clear, and fully cooked fish flakes with a fork. Sausages take patience, so cook them at least 25 minutes or so. Especially when I'm looking for a turn off, and someone pulls up behind me and rides my bumper. This really isn't the type of tailgating that I was referring to, and if you fit into this category then I urge you to read on and learn how tailgating partying is a ritual of food, fan fellowship, and fun. They pack ready-made sandwiches, potato salad, cookies, cold fried chicken, chips, and lots of sodas.