If it is such a Gordian knot that you can't follow the cables by hand/eye I found that the quickest way of doing it is the following:
- Make sure you've got approval for downtime.
- Take a laptop to the patchpanel.
- Unplug the first cable from the patchpanel and put it in the laptop.
- Plug/unplug it a couple of times and keep an eye on the switch which port goes up/down.
Use 30 second intervals. Some switches take a few seconds to react to plug/unplug.
- After you identified which port has this cable label both ends with the same number (so you know which ends belong together in the future). Just use numbers. Don't try to put anything meaningful on the labels. You are bound to hook up something else to that cable in the future, necessitating re-labeling which is a nuisance.
- Repeat with the next cable until done.
This way you limit the downtime per device to just a few minutes.
If the patchpanel and the switches are not in visible view from each other get a co-worker to do the other end and keep synchronized by phone, walkie-talkie or just shouting if you are close enough.