Buy adjustable CTR rings (for CTR class in Primary), soak in nail polish remover 5-10 min. and use a pin to clean out the little groves (it's pretty easy), once it is silver you can leave it or use fingernail polish to change it to your child's favorite color. Carefully wipe off the letters and anywhere else you get nail polish, that you don't want it, with your finger or a tissue. You could even put a coat of sparkles on top. Less than two dollars a ring.
LDS General Conference Activities for Kids #LDSConf