For a spicier kick, add a pinch of cayenne pepper to the chicken marinade. Feel free to substitute grilled chicken or rotisserie chicken for a quicker preparation. To prevent browning, store leftover guacamole in an airtight container with a layer of plastic wrap pressed directly onto the surface. Customize your tacos with your favorite toppings! Consider adding pickled onions, crumbled cheese, or a drizzle of hot sauce.