We don’t have a lot of dirt to play in around our house so when we took down our pool last week kids were immediately drawn to the large dirt circle left behind. After a couple of hours my daughter looked like this (although I told her to give me the scary look).
Strobist info: AB800 with 7′ reflector behind her and an Einstein with 20 degree grid as the key light.
As an aside, if you’re ever in need of a costume for a photo shoot check out Costume Nation. I got a couple of great bear costumes a while back.