I think my most persistent bad habit is forgetting to turn off the iron. My bad habit I seem to have conquered is misplacing my tools. Now they all have a place to live and I make sure they go "home" when I'm done with them.
BJ.........you could try plugging ONLY your iron and a small lamp or night light into a strip and turning the light on. You will know when your leaving the room that you havent turned the iron off if the light is still on. Sure has helped me.