Start by removing a half inch off the top and bottom of the watermelon.
Stand the watermelon on one of the cut sides. Using a sharp knife, starting from the top, and following the contour of the watermelon, carefully peel the skin off, about ½ inch in depth.
Continue to peel the watermelon, taking off 2-3 inch wide pieces of the peel following the white inner peel color, being sure to cut deep enough to see only the flesh.
Cut the watermelon in half vertically then each half in half again to give you four manageable quarters.
Cut into desired shapes and sizes
For triangle cuts: lay the quartered watermelon on one of the flat sides. Then, cut down vertically. You can then cut each triangle into cubes, or
For cubes: lay the quartered watermelon cut side down and cut into triangles. Then, make perpendicular cuts lengthwise. Rotate the stack to the other original cut side and make more perpendicular cuts to create a grid pattern of watermelon cubes.