These ideas could be used for any loving holiday:
Mother's Day, Father's Day, Birthdays or Valentine's Day!
Glue random puzzle pieces to a picture frame - Can be painted or left as is.
Glue a few pieces to front of a card and write "I love you to Pieces!"
Draw a heart shape on paper and cut out. Let toddler glue the puzzle pieces inside the shape. Paint red. Glue onto front of card.
Glue puzzle pieces to a small flower pot or container.