I started off by using a sound trigger but soon discovered that the flames made enough sound to trigger my camera. I then decided to use a laser trip wire and drop something through the laser... somehow though when the flame would cross the laser it would trigger my camera. Eventually I sort of got it to work before the glass cracked from the heat. This one is probably my favorite even though the ring has already hit the bottom.
In case you were wondering: Yes my wedding ring is The One Ring.