I no longer use file folders for storing master copies of worksheets. I am known as the plastic sheet protector queen of my school! I place all worksheets in a plastic sheet protector with the answer key on the backside. Papers don't get lost or mixed in with other copies because the plastic protectors don't need to be removed for photocopying. I use post-it notes to record the date the assignment was given and if there are any necessary revisions that need to be made before using it again next year. All related worksheets are organized into three-ring binders with indexed dividers. No more lost or scrambled papers because I dropped my file folders!