Standing desks are a pain to cable manage, especially when they're put together backwards (oops). I've been meaning to do this forever. Given the cables for the motor running the way they are, I'm happy with it.
I had some pieces of upholstry leather that I salvaged from my old desk chair for future art projects. I cut strips of it to make loops and then used a staple gun to attach them to the bottom side of the desk.
Headphones are just hung there on a hook, usually neater, but they got knocked around while I was moving the desk to get behind it.
I'm pretty happy with how the workspace is looking these days.