For all creations you would never want to have to do over again from scratch, best practice is to save incremental versions... eg: <filename>, <filename>1, <filename>2 or some such system you find meaningful. And store your critical files offsite as backups... eg: on a cd or memory stick, portable hard drive on your person, in your vehicle, on X drive... or somesuch. You'll never be sorry you had a good backup system in place if disaster strikes in some form... hard drive failures, fire, flood... pick your favourite disaster. I work in two different locations entirely, so always have all my work on the original hard drive the work was done on and another hard drive in the 2nd location. A memory stick makes it easy to transfer the files... from Town Office or from Home Office.