I like to do a variety of projects, from building guitar amps, to maintaining a couple of vintage cars, to restoring old machines. And often my attention is interrupted by dinner, kids, or phone calls.
To bring some order to these projects, I’ve collected old cupcake pans. I find them invaluable in keeping things separated. The typical cupcake pan has 8 cups. I number them 1-8 with a sharpie.
If I’m working on an engine, I might use the numbered cups to correspond with cylinders. With some projects, the cups might represent a rough sequence in which the parts were removed (and later assembled). With other projects, they might represent the physical location of small parts with respect to a larger object. If I’m interrupted, I can set the pan aside and know things are still in order.
I’m sure you can buy these new. However, I found them easily enough in the kitchen section of the local salvage yard for a lot less.