Cut out a heart from pink construction paper. The heart should be larger than the front of the paper bag.
Cut out another heart, half the size of the first, from red construction paper. Glue this heart to the center of the larger heart.
Place the glued hearts on a doily. Cut a heart shape from the doily, slightly wider than the pink heart. This will add a frilly lace edge. Glue the colored hearts to the doily.
Decorate the bag with colored tissue paper and construction paper.
Write the name of the mailbox maker in the center of the pink-and-red heart. Decorate around the name with sparkles, paint, small cut-out hearts or drawings.
Glue the heart to the front of the paper bag. Open the bag and hang it from the child's desk with tape.