Spray paint the ornament with the paint color of your choice. Use several light coats on both sides and let dry.
Create your tattoo following the printable temporary tattoo paper instructions, or choose a pre-made design. Cut out with scissors just around the design.
Apply your tattoo to the ornament using a wet washcloth. If you painted your ornament, make sure it is 100% dry before doing this step, or you will wipe the paint right off.
Spray the ornament with protective enamel spray to seal the tattoo.