Fill a wide and deep plate (it is desirable to take a gauzy plate or cut-glass ware) with water. Put some heads or petals of flowers on the water. And don''t forget to put floating candles there.
Fill a large glass or a small jar with flower heads or petals. Try to put them so they could face the glass. Put a long candle in the middle of the glass or the jar.
A little remark. If you don''t want the ordinary jar to spoil the impression by its not aesthetical look, turn it into an unordinary one.
E.g. smear the neck of the jar with some glue and plunge it into sugar or salt.