Without making this too techie, the age-old method of backing up includes daily, weekly, monthly. if going back 12 months won't get you a good file, i'm afraid you're the messup. not the backup. i have one directory on all my computers that holds everything i edit or receive or want to keep. it's trivial to make a backup of 1 directory. if you store documents here and there on your computer and that's working for you, go for it. if it seems that you're doing a lot of work to keep current backups, change. it's your choice.
oh, and my 1 directory is never on drive c (windows machines). that way i can just make an image of my boot drive and if it goes south, it'll take perhaps 15 minutes to rebuild.