Dude, the holidays are coming up. Once again you'll be pulling out the cords... Halloween lights, Christmas lights, extension cords, and they'll be all tangled up again. Sure, 10 points for Hogwarts for your effort last year, but it's a tangled mess again.
If you'll follow this technique, NO MORE tangled tethers! And that's just awesome!
You will thank me NEXT YEAR.
The "over/under" name refers to the practice of twisting the cable in one direction to make the first coil, and un-twisting it to make the next, and repeating this until all the cable is neatly coiled. Care needs to be taken to keep each end on its proper side of the roll when uncoiling otherwise a knot will appear with every other loop. Connecting the ends on the outside of the loops, or tying them in that position, insures that the ends don't pass through the loops in storage so there are no knots when the cable is laid out.