[arethuza]

Occasionally try restoring your backups and check that the really important stuff is still in a usable form.

[trafficlight]

Also, every few months take a few minutes and make sure that you really are backing up what you need.

I had a client a few weeks ago that had a drive failure. We went to restore from his offsite backup copy and found that some of the files he needed weren't being backed up. A quick review of the backup job would have caught this.

[entreprenewb]

And conversely, make sure you aren't backing up what you don't need.