Several years ago I happened to have an empty aquarium sitting outside, and one winter morning its glass faces were covered with intricate from flowers.
Using a flash from the side created beautiful highlights and eliminated distractions in the background.
I have not been able to reproduce this. I would be fascinating to make a time lapse video showing how these actually form.
This, however, requires more optimism and patience than I have.
I wish these images here had the ability to decay like the frost flowers. Instead, they are truly digital: They are, or they are not.
The Inner Frame 