Seven years later it was neither neat nor tidy. As I continued to acquire wood and generate still usable scraps it all got thrown on top of the pile, and not neatly stacked, either. Even if it had been neatly stacked, with only two layers anything at the bottom of either layer was impossible to get at anyway. Plus, being under an open staircase, all the dirt and dust that got tracked on the stairs eventually wound up on the pile, too.
I wanted to build a couple of projects recently, and when I looked at the pile to see if I had suitable material, I realized I had no way of knowing what was in the pile. I considered building some sort of tiered rack under the stairs, but in the end I decided it would be easier to buy one of those heavy duty stainless steel wire shelf units. I already have a couple, and they're simple to put together, not that expensive ($75 at Sam's with six 4' by 18" shelves, 6' high), and very sturdy. The casters are nice should the need ever arise to move the thing a little bit. I also got a smaller 6' high unit for $40, the lower half of which is going way under the stairs to provide additional support for the really long boards (8' and longer) on the lower shelves that would otherwise be just hanging out in space, with the potential for warpage ever present. The top half of that unit will become the bench upon which my router table will finally find its permanent home after years of commuting between the floor and the top of the table saw.
It was a dirty, dusty job. I had to vacuum the dust of the ages off each board as I pulled it out, and then I had to find someplace to stash it temporarily. This turned out to be, among other places, the tops of the washer and drier, which meant I couldn't do laundry until I finished. This provided ample coercion to get me to complete the job up by the end of this afternoon. Fortunately, it all went smoothly. I had to shorten two of the poles on the big shelf unit by an inch to get it to fit under the stairs, but my trusty hacksaw was up to the task. The only tricky part turned out to be maneuvering the really long boards (10') down onto the lower shelves what with all the other crap that's in the way down in the basement.
Now it's all neat and tidy, and boy do I have a lot of lumber. A good portion of my stash is pre-Revolutionary War chestnut barnboard salvaged from the exterior walls of the old schoolhouse my brother added onto to build his old house. I've had it for about ten years now, just waiting for the right project.