Pour some of our diffuser oil, simmer oil, or other warming oil into the glass bowl, and warm from underneath with a tea light candle. Caution: Do not allow to boil. Simmer over low heat. Directions: Pour full strength into a simmer pot or oil burner and simmer. Continue to add additional refresher oil as the liquid evaporates. Rinse container after use. Do not leave oil burner unattended.