I had fun yesterday shooting abstracts of the autumn leaves up here in New Hampshire. Here’s one that turned out nicely. If you want to try this yourself, fit a zoom lens and select an exposure that gives you a long shutter speed (1/10 to 1/2 second seems to work best). Point the camera at an area containing a mix of colours, hold the camera by the lens zoom ring and release the shutter while rotating the camera body so that you zoom and rotate the sensor while the shutter is open. You can try variations on this, for example, zooming with the camera body stationary or moving the camera up and down during the exposure. Generally, I find that most of the results are rubbish but a few like this one will jump out and work really well.
For the technically inclined...