You will need a nice large watermelon. Slice the watermelon into large slices about 1 1/2 inches thick (or whatever size best fits your glasses). Remove the rind and cut each of the slices into cubes.
Places the cubes onto a sheet tray. Wrap the sheet tray in plastic wrap and freeze the cubes for a few hours, or until completely frozen. If not using them right away, place the frozen cubes into a resealable plastic bag for easier storage.
Add to garnish a nice glass of water or use to divvy up a fancy cocktail!