I was reading the sample of Melinda Lo's ASH and she wrote something that struck me as odd. The main character's mom is dead and her father lights a candle that burns for three days. Now candles aren't made to last that long, and that got me thinking. What if creating one's own funeral candle was a culture's death ritual.
What you use for wax and wick have meaning. What you include to melt in (or out of) the wax has symbolism, etc. Each life millstone and personal accomplishment add to the candle, thus a person's life can be measured by their candle.