A client told me he could not connect to the Internet. When I arrived at the house, I saw that the ethernet cable was not plugged into his laptop. I connected the cable, rebooted the computer and, voila, Internet. Later, we unplugged everything and connected wirelessly. I did not think to figure out why he was not previously connecting wirelessly, so I that’s a mistake on my part.
But I did do this part right: I put a label on his laptop above the ethernet port, a label on the wireless router above its ethernet port and a label on the ethernet cable itself.