Photo inspiration only. Ideas :: Trace pattern (lightly denting candle) onto the candle from a print out (laser or inkjet should be fine) ? Use puff paint from the fabric paint section of your local DIY store to finish it off.
Henna Art Candles - Tutorial not included in article. I would take any candle of choice, scented/non scented, either use delicate paint brush or a henna paste tube (looks like a mini cake icing tube), and decorate. Just stick the gems on with henna.