We start by laying a large flour sack dishtowel out on our table. We made a quick diagram (above) because although this is a simple thought, it's best drawn instead of photographed, as you will soon see.
Using your average and most basic knot, tie corners 1 & 3 together. Next tie corners 2 & 4 down over the first knot. Once more tie 1 & 3 to hold the whole thing tight. You will now be able to pick up all 4 corners and sling it over your shoulder (like a continental soldier) as you head out the door.
The knots keep it from rolling around the floorboards or seats of your car as you drive to your destination (hell hath no furry like a watermelon on the loose!). It will still turn until it hits the knot, but shouldn't go sailing around under your feet. If you're walking to your party, it's easy to pick up by it's handles and carry without the fear of slipping and splattering on the ground.
Wrap it up in your favorite dishtowel and leave it with the hostess, or bring a second one just for her to enjoy once all the guests have gone. If you don't have a dish towel large enough, try using a reuseable grocery sack, making sure the seams will hold the weight of your chosen melon!
Related: Recipe: Watermelon Popsicles