I often look for water drops hanging precariously from objects in the open during monsoons. Like a mirror, the image visible in the drop focuses on a different plane from the object the drop is clinging to. I experiment with focussing on the drop as also on the inverse image of surroundings inside the drop with various settings to check the results.
Canon 60 D
100 mm Micro on manual focus, about 1:1 magnification
ISO 200
1/6 second with f/14