Valentine Card Holder using tissue box
I'm sorry if this offends anyone out there (teacherly types do tend to get prrreeeety defensive about their choice of Valentine mailbox crafts) but this is the COOLEST VALENTINE BOX/BAG EEEEEVEEEERRRRRR!!! One thing I would change about it, though, is that I would offer construction paper hands to my students in a variety of skin tones.
Hot Air Balloon Valentine Box
Valentines Boxes for Kids
Paper Plate Valentine Boxes