• cable trays of various sorts
  • rain gutters
  • Ikea cable tray
• zip ties
  • zip tie everything
  • pegboard covering the entire underside of the desk
  • another pegboard
  • zip tie to a wire shelf
• binder clips, screwed onto a board
• hacked up plastic box?

random tips

• use old toilet-paper-roll tubes to tie up stored cables
• use cable clips to tidy up cable ends, particularly ones that are sometimes loose (charger cables)