Back them up
The one thing I stress to all of my clients, is that there is no such thing as to many backups. I also stress the fact that nothing lasts forever. Technology "WILL" fail at some point. In addition to backups to USB drives and DVD, I also stress to physically print the return will all calculation forms and worksheets to physical paper, and to store it in a safe place. The more printed copies stored in various secure locations, the better. When the day comes that the technology fails you (and it will), you'll be thankful to "wasted" the time with hard copies.
One thing I do discourage, is online backup. I have a problem with storing everything needed to steal my identity on a device which I don't have direct physical access to and complete control of. Therefore I don't use things like OneDrive or IDrive for any personal and sensitive information.
