Some unique thank you note ideas that can be used for birthday wishes include sending a photo of the recipient with the gift, making origami objects, writing "thank you" on several hearts, turning the gift's name into an acrostic and taking a photo with a chalkboard that says "thank you," notes RealSimple.com. These ideas can be used as creative ways to encourage children to send thank you notes.
One unique idea is to make brightly colored origami paper into different shapes, such as hearts, snowflakes, flowers and stars. The shapes can be pasted onto blank card stock. Another option is to cut out half-hearts in different colors and paste them onto blank card stock. Write "thank" and "you" on the different halves of the hearts.