Long-handled tongs, basting brushes, and spatulas are helpful for tending foods while cooking. Heavy-duty oven mitts also can be helpful.
With a grill wok, you can stir-fry on your grill. If you like grilled pizzas, consider purchasing a grill pizza tray.
A grill topper is quite versatile and can be used for grilling fish and vegetables. It provides an even cooking surface on the grill that prevents foods from falling through the grill rack.
For kabobs, keep skewers in assorted lengths. You may want to try grilling them on a skewer rack.
You can purchase an accessory metal smoker box for your gas grill to hold soaked wood chips.
Keep your grill racks clean with wire brushes and scrubbers. You can also use crumpled pieces of foil to remove build-up on the grill racks.