Smaller vase inside larger to decorate vase. Floating candle in the middle. Could do it with lots of other things besides lemon slices such as beads, pearls, flower petals, fabric, ribbon. Possibilities are endless!
Shepherd's Hook With Mason Jar Bouquet. Just tie heavy twine or wire around the mouth of the jar, fill with water and fresh flowers, and hand on the hook. You could also fill with just sand and tea lights for a rustic outdoor event.