Using these natural onyx candle holders is a breeze. Just place a candle, either real or flameless, inside the holder. For a more relaxing effect, choose flameless candles in natural or warmer light colors. When it comes to placement, you can put them indoors in your spa's relaxation areas or outdoors on a patio. As for maintenance, simply use a soft, dry cloth to gently wipe the holders clean. Avoid using harsh chemicals as they might damage the natural finish of the onyx. Also, be careful when handling lit candles to prevent any wax spills or fire hazards. Enjoy the calming and beautiful atmosphere these candle holders bring to your space.