Having problems with messy cables? Here's how I dealt with it.
Most people might suggest using tie straps, but the problem with that is how tough it can be to disconnect peripherals after doing so. this solution involves using PVC trunking instead.
As seen in this image above, I have mounted the trunking on the back of my desk, and routed the wires through it. This redirects the wires to the back of my PC, rather than having them hanging behind the desk and being visible from the bottom.
Mounting the trunking is simple, if you have a wooden desk, you will need at least 2 1" wood screws. I used a screwdriver to manually screw the trunking onto the desk with sharp self tapping wood screw to hold it on securely.
You may also want to cut openings in the trunking, like in the image above.
Assuming that your trunking has a removable cover, all you need to do is peel it off, and run your keyboard, mouse, monitor, and whatever cables through it. One that's done, you can put back on the trunking cover, and you should have something like the image above..
In this image, you can see where my cables come out at the back of my PC. The idea is that when the desk is pushed against the wall, these cables will be hidden by the desktop tower itself. I did not do a great job here, but you can roll up the cables behind the desktop if there's excess wire.
Now, lets see what the final result is like!
No wires under the desk, just as I hoped!