OK, not the most exciting thing I've ever done, but it will make things a little easier.
FlexSteel is a steel-impregnated rubber sheet. I get mine from Litko, cut to the sizes I need. It has an adhesive side, so just peel off the backing paper and stick it to the bottom of my bases (so they will 'stick' to my magnet-lined storage boxes).
In the old days, I just dumped all my FlexSteels into a drawer, and searched out whatever I needed.
Then I advanced to bagging most of the FlexSteels (or leaving them in the bags they came in), but I never finished bagging them, so I had loose ones in the bottom of the plastic storage bin. And I'm making sure all of the bags are marked by size.
So now I'm bagging them all, and I'll make an index sheet so I'll know what I have at a glance.
Nothing exciting, just a slight improvement in my painting room.