Decorate cookies. Prepare decorating bag with coupler and green icing. Using tip 5, pipe melon rind on each cookie. Let dry, about 15 minutes.
Prepare second decorating bag with coupler and pink icing. Using tip 5, pipe melon on each cookie. Let dry, about 8 to 10 hours.
Prepare third decorating bag with tip 2 and black icing. Pipe small hearts on each melon. Let dry, about 4 to 5 hours.