Go vertical: Store papers using vertical-end tab files or better yet, nine-by-twelve envelopes stored upright in magazine holders. Vertical solutions do not lend to pile creation.
Three-Sided Storage: The standard file folder has always been a mystery to me. Why would someone opt to store important paper for “safekeeping” in something that is open on three sides? Convert to large envelopes, expandable files, or other storage solutions with three-sides sealed to avoid paper overflow.
That was then, this is now: Clearly separate your current paper from your archives. Keep archives in a dark area of your home that is inconvenient. Anything in your archives should be rarely needed and thus not receive prime real estate.
Index everything: On the front of every storage holder (envelope or file) make an index of all the contents for quick reference. This avoids the “big dig” which often leads to strewn papers we opt to put back “someday.”
The one with the most files—loses. Having more files and categories does not make you more organized or more efficient. Having more files and categories gives you a system that is harder to maintain. Create files only as you need them. My rule of thumb: Use one file until I have over a half-inch of paper and then give it its own category.