You show a unlit candle on a stand and proceed to light it. You then cover it with a tube that is shown to be empty. When the tube is lifted the candle is shown to have transformed into a bouquet of flowers.
This is an very old effect but still evokes the same response as it did when it first came out. This Candle to Flower is very well made and will last you many a performances.
This is a very visual and easy to do trick.