I have seen "smoke photography" done before, but never tried it until tonight. It's tricky, but when you get one that works, a lot of fun. I found a great tutorial on how to do it, though you need some gear and patience. I didn't have incense, so used a candle which requires some extra lighting and re-lighting steps (and you end up with smoke everywhere!)

This image has a bit of spiritual quality to it. See what you can find.