I posted my "Turn-In Trays" on Instagram and received lots of questions about them! This is how I have my students turn in their completed work. I love this because it takes up very little space and keeps the subjects separated. I also train my students how to lay the papers in the trays all facing the same way, which saves a ton of time with sorting! At the end of the day, I have a student stack all of the papers up for me and clip them together.
I purchased these trays at Staples almost 10 years ago! I found a link to them HERE.
I created subject labels and a header card, printed them on card stock, laminated them, and hot glued everything to the trays. If you'd like to purchase the labels I used, you can find them HERE in my TpT Store. The download includes a PDF of the exact labels I used. I also included a PPT file where you can edit the subject labels.
Hope this helps! :)