I know I am late on this, but here are a few photo techniques I played with. For the levitation photos, I put my son i a giant sling shot, and sent him sailing across the salt flats. Okay, not really. The lighting was flat, and the values were very continuous. It was rather simple to photoshop in a fake shadow, even though I think I could have spent more time to make the shadow just right.
I also tried some painting techniques. It wasn't bad, but a large part of it was using filters with some hand work. I think it would be more natural if it was all hand converted. But it was till interesting results. I had another image that I shot HDR, processed it with a painterly feel, and then ran some conversions. I cannot seem to find that file anywhere, but I will post it if I find it. I thought that method also produced some nice results.
And of course the tilt shift technique. Not a lot of points for originality since Joe already posted some, but I thought I would still share.