I use paper plates with the sizes written on the plate to keep more complicated piecing parts organized. If there are parts that can be chained pieced, I just take those plates to my machine and piece away. If I need to put them aside at some point, I put them in a plastic 12” block tote/organizer box. I’ve reused those plates many times, crossing out the old sizes and adding the new ones. Inexpensive and it worked for me.