Plastic toys from the dollar store or thrift shop are great pieces to start with. The plastic is softer and very forgiving if you end up needing to take a few tries to get the hole drilled out. They are somewhat large for your basic door knob or drawer pull, but could work on the right piece.
In this manner, how do you decorate drawer knobs?
1 Paint your knobs with 2 coats of primer; let dry after each coat. 2 Paint with a coat of white paint; let dry overnight. 3 Download the design and print it out. Make a color photocopy of the printout (inkjet printers will not work), enlarging or reducing the design to fit your knobs.