Get a "Cable Management Box", actually get several.
Everywhere you have a power strip you should have one of these. It helps contain the mess of cords, hides it away, and prevents them from being dust/spider/hair traps you don't want to touch. Shove the extra cable inside the box so you don't have a extra wires laying about. You will absolutely love not seeing a rats nest of cables, even if it's just behind/under something.
I won't link to any product because they are all the same. It's just a plastic box with 2 holes/slots on the sides and a lid. It's stupid-simple but it's worth every penny. If the box is visible I guess you could spring for the more expensive ones but I usually get a 2-3 pack for $20-30. I don't think I've ever bought the same brand twice since are all the same and I just pick the cheapest that fit my needs (size).
Search for "Cable Management Box" and you'll find it.
You'll probably also be interesting in "6-Inch Power Extension Cable", they are great for wall warts. You can plug multiple of these into a power strip and then hang the large heads off to the side (instead of blocking multiple ports). And all of that stays tucked away in your cable management box.