Some recipes state to marinate meat and poultry for several hours or days, either to tenderize or add flavor. Always marinate food in the refrigerator, not on the counter. If some of the marinade is to be used as a sauce on the cooked food, reserve a portion of the marinade. Don't put raw meat and poultry in it. Don't re-use the marinade used on raw meat or poultry unless it is boiled first to destroy any bacteria.
Some people like to cook food partially in the microwave, oven or stove to reduce grilling time.
Pre-cook immediately before grilling to destroy bacteria. When carrying food to a picnic site, keep it cold to minimize bacterial growth. If take-out foods such as fried chicken or barbecued beef will be reheated on the grill, and they won't be eaten within two hours of pickup, buy them ahead of time and chill thoroughly. Use an insulated cooler with sufficient ice or ice packs to keep the food at 40 deg. Then pack food right from the refrigerator into the cooler immediately before leaving home.