Electrical installation: how to label wires?

Heat-shrink labels all the way. They never fade or fall off. But you may not be able to use them if the cables already have connectors at either end.

You can get nice little labelling machines to write neatly on them.

Alternatively, try cable clips, which can be clipped on after the connector.

Another great one is these twist on cable labels.

There are literally dozens of solutions to this problem. If you want to google it, the key words are cable identification.

I cut narrow strips from self-adhesive labels, which I wrap around the wire and stick the ends together so they stick out as a little flag. You can write a lot on a cm length!

I've actually struggled with this same problem. I have a small home music studio with a dozen MIDI, USB and audio devices. There is a rat's nest of cables and it's difficult to tell them apart.

My solution was to have some custom vinyl stickers made up. The nice thing about this as opposed to some of the solutions mentioned above is that I was able to customize the colors and patterns of the stickers so I can tell at a glance what is paired up with what.

The label printers are nice, but it is not really an ideal solution for quickly identifying cables.