Wrap box in construction paper. I used a Capri Sun box because I thought the shape was very LEGO-like.
Use a box cutter or X-acto knife to cut a hole for the valentines.
Paint milk jug lids with red paint. Let dry for about 30 minutes, then add a second coat.
Because I used a flat paint, I painted Mod Podge over the top for a glossy look. You may or may not want to do this if you don't use glossy...totally your choice.
Once the milk jug lids are dry, use hot glue to glue them to the box. If your child is too young for a glue gun, they can use regular white glue instead.
So easy right? Now you have a super cute LEGO valentine box for school!
Notes
Be sure to save your milk jug lids ahead of time to make this one!