Something else which is fun to experiment with is a double exposure at two different apertures. One wide open and one closed down to give a large and narrow depth of field of the same image. It's a bit more complex though as you need to work out the correct shutter speed for each aperture value then use the next highest speed to give half the exposure for each.
e.g. if your normal exposure is going to be f8 at 1/60 and you chose to make an exposure at f2.8 and f16, your shutter speeds would need to be 1/500 and 1/15 respectively.