1. Cut approximately half a seedless watermelon into cubes (enough for 8 cups) and put in freezer to chill (Make sure that if you put them into a freezer bag that you break the pieces up every now and then to prevent huge frozen chunks). Once chilled or frozen to your liking, squeeze 8 limes or so (depending on size) for 1 cup of fresh lime juice. Combine the lime juice and 1/2 cup sugar into blender before adding the chilled watermelon cubes. Blend all together, pour into glass, garnish to your liking (lime or watermelon slice, mint), and enjoy!