Use the sharp knife and cutting board to dice the watermelon into roughly 1-inch cubes, ensuring uniform size for even distribution.
Slice the avocado in half lengthwise, remove the pit, and carefully peel off the skin using a spoon or fingers. Cut the avocado into thin slices or chunks.
Transfer the cubed watermelon and sliced avocado into the mixing bowl. Gently toss with a spoon or salad tongs until evenly mixed.
Inspect the mixture for even distribution and vibrant appearance. No additional dressing or seasoning is necessary, but you may optionally add a pinch of salt or lime juice for flavor.
Serve immediately, displaying the bright red and green colors of the fruit, with a glistening, juicy appearance.
