Tip from a friend that I began using 3 years ago, after teaching for 15 years:
1. Use 3-4" binders, label w/subject on spine, use protective sleeve covers, index dividers (numbered 1-25, that what fit in a 3" binder)
2. Put a Master copy of the worksheet w/an answer key in a sleeve, I usually have a page that goes w/the worksheet to put there also (menu, article, brochure...I make most of my worksheets from real life items)
3. Separate worksheets w/index dividers
4. Create an Index with the number on the divider and the worksheet name, put the Index in front of binder.
Binders are easy to stack and move. Because I create most of my own worksheets from real life items, I also have the worksheets on a flash drive in Pdf form for backup.
This idea has cleared up the disorganization of my paper stuff and given my more room in my classroom, and in my house over the summer! Because I will be moving to a new school w/in our district this year, as yet to be determined, this consolidation will expedite the move.
Hope this gives you another idea to think about.