I tried numbering/lettering the cabinets...it was CONFUSING for everyone. This way I don't have to tell students where supplies are kept or go fetch them. MWHA HA HA (evil art teacher laughter)
I just broke down and spent the $4 at the big box store (which I don't want to openly endorse) for these bins...I was using cardboard boxes but they were pretty raggedy and didn't have lids. It eliminates me having to track artwork around the room or call in an excavation team to find my desk!
In both instances if students "don't know where something is/what to do with unfinished artwork" I tell them, without any sarcasm, that I think they can figure it out...well maybe I raise an eyebrow;)