If the back of your desk is a rat’s nest, here’s a cheap way to manage those cables.
This method uses a $4 box of large binder clips, plus some screws and washers. You may find it’s cheaper to buy a box of screws and washers as well.
I worked in a shop once where they contracted out the cable management. Calling those guys perfectionists was the understatement of the century, but their cable runs looked like a work of art.
There seemed to be two keys. One is getting your cables a uniform length. You can’t necessarily control that completely, but you can bundle up the slack space somewhere that it won’t be visible. The other key is bundling the cables tightly at regular intervals. Velcro strips are invaluable for that, though you can use cheap and cheerful wire ties if you don’t move cables around very often.