Decorate the base of the jar. Add such items as sand, glass pebbles, mini plastic toys, faux gems or anything else you find pretty and that can cope with getting wet.
Add water. When adding the water, only turn on the tap low; that way, you won't spoil the decorations or wash them out of place. Or, use a pitcher or jug and pour slowly.
Squeeze a layer of vegetable oil on top of the water. Add enough to cover the top completely.
Find a piece of wick one inch or 2.5 cm in thickness.
Cut the Vacuform tray to fit the width of the jar.
Stick the wick into the hole in the Vacuform tray, with the domes of the tray facing up.
Make sure that no more than 3 mm of the wick goes through the bottom of the vacuform tray.
Set the Vacuform tray with the wick over the oil into the jar. The wick should not extend into the water. (Manipulate the decorations to help support the Vacuform tray up higher.)
Finished. Light your water candle and enjoy its ethereal glow.
*This candle should not be moved once lit, owing to the hot oil. Therefore, light it where you expect to leave it.*