For my sons first Valentines Day at Preschool we made heart shaped rainbow crayons. It was easy and fun. We used crayons that were already broken and some that weren’t. We broke them into small pieces and put them in heart shaped molds that I bought for a dollar at Target. We placed them in a Pyrex pan in the oven on 250 degrees for about ten minutes. Then because my son was anxious for them to harden I stuck them in the freezer for about a half an hour. Then I glued them onto card stock. They turned out so cute and he was so proud of our homemade Valentines.