1.
Spread the puzzle pieces out on the newspaper (you can use border pieces, corner piece, middle pieces, etc.; anything goes!). Spray paint them using the red spray paint. It's best to do this AWAY from the kids, or do it outside, keep the kids at a safe distance, and have them wear masks covering their noses and mouths. Alternately, can simply use red paint and paint brush to paint each piece, if you don't want to use spray paint at all.
4.
In the middle of the poster board heart, use the marker to write, "You've got a piece of my heart!" or any other message you choose.