I’m a strong advocate for never throwing any design work away, especially now that electronic storage is so cheap. I use Dropbox, iCloud, and Adobe Cloud to store my files, and I admit that my sloppy filing system resembles Pathak’s joke. While it’s arguably irritating to have multiple versions of the same file, not having what you need–that you already created once–when the client changes his mind again is far more frustrating.
My advice? Save everything. Save work outside your artboards, you know, in the grey, unprintable areas.
My best tip? Keep unpathed/non-outlined fonts in the original files, just out of the way. When you open a long forgotten file, the program will prompt you for the font, even if you’ve removed it from service in Font Manager.
The alternative to not doing so? Spending 45 minutes trying to determine the font you used on a job from six months ago that you pathed to prevent problem for the client and service provider. Wasn’t that thoughtful of you?