I've seen this on a website long ago, and have been using this method ever since. It's so easy, so I thought I should share!
You know those little clips with dates stamped on them? Use them to tag your cables! Chargers, Lights, Sewing Machines, Computers, Printers, TV, DVD Player, Router, etc... See? Confused already? That's why you should do this!
It's free, easy and good for the environment too!
(Image taken from here.)