A helpful tip for any game designers out there.  Or, honestly, anyone who ever does any important work on a computer.  Back things up regularly.  I learned that lesson as a teenager when some computer issues combined with a bad tech support worker resulted in the system getting formatted.  Fortunately, I did actually keep copies of my most important files on a CD-RW at the time, but I only updated it every so often so I lost about a week’s worth of work.  Could have been worse though.  Ever since then, I’ve been much more careful.

More recently, the critical system failures I had to deal with could have been utterly disastrous (for Aurora’s Nightmare, among many other things) if I didn’t keep everything backed up.  While backing up your files to external media never hurts, these days I’d say the best way to go is with a cloud backup program.  It will automatically back up all the designated files and folders and your computer in the background as you work to a secure sever.  There’s a monthly fee but, so long as you have an internet connection, you’ll never lose more than a few minutes (or, at worst, a few hours) of work.  You may even be able to retrieve old versions of files if you accidentally deleted or saved over something.  And, since everything is backed up off-site, it doesn’t even matter if your entire house burns down, you’ll still have your files.  Personally, I use Carbonite, but there’s several good services available.  Even if you don’t have anything really important to save, the convenience alone is probably still worth it.