Organizing your office to be more efficient can likely mean polishing up your filing system. Providing you have an in basket , you can begin .
As you go through your basket ,determine what file it should go into. Give your files names that will be easy to recall . I made a listing of my file folders and what is in each file drawer so that I do not have doubles in my cabinets ( see The Organized Librarian book). Another good idea would be to make a file index to go in the front of each file cabinet or drawer. This will help you locate files you need quickly .
You may also want to figure out how long you will keep files. If they are dated , then you can easily look at the items and determine if new material has been inserted and if the old can be thrown. If you do this on a regular bases then your files will be current ( and not overloaded with outdated materials)
Take time each day or week depending on your schedule to go through your in basket. I have three files into which I mark : To Do, To File, Catalogs.
I only keep catalogs that I know will be useful or that I will order from. These are kept in a separate file drawer marked by letters. When I file a new one , I throw the old one out unless I have marked some items/ titles for purchase.
I also have historical files that I keep for reference. These would be budgets from years past, book requests from staff, old policy's, handbooks, old curriculum, and other items that I do not use , but like to keep to refer to if needed.