I know I post a lot about mail, but I can't help it. We love it. Postcards are a simple and less expensive way to send some love... The easy way to make a postcard is to get a couple 4x6 index cards and glue them together (for stability). Then let your child go to town decorating the front side and then writing a message on the backside. If you don't have index cards on hand, you can always cut some heavy paper and make them that way.