Thank you (in advance) for sharing your knowledge and/or experience...

Welcome and I got just a couple of points I want to bring up.
#1- those plastic totes come in real handy for your scrap. But boxes come cheap, I use banana boxes from a discount grocery.
#2- Circuit boards are not necessarily "motherboards" unless the come out of a computer/server. TV/stereo scrap is just low-grade circuit boards.
#3- On small items it's hard to tell the difference between alum. and stainless (weightwise) I'd throw that stuff into a box of it's own and mark it ? so that way you can let the yard explain it to you. They have seen enough material to pretty much tell whats what.
Even tho I threw them a curve ball at my yard with some computer scrap, they had to bring out the gun.