Playful Organizing/Other Tools
Labeler
This has worked well. Create labels for clean looking files. Buy a professional label maker and leave in plugged in. Better yet, have two, one for work and one for home.
Hanging Files
This has worked well. Label both the hanging file and the folder with the same name. Have one for each folder. Put in alphabetical order. Then if a file is removed you know exactly what is missing and where to put it when found.
further reading
edit- The 43 Folders wiki describes the "tickler file" and other organizing tools.