My first use has been simply framed as art work, because they are so beautiful. I wouldn't be surprised if someday I have at least one hanging in each of the rooms in my house. Actually, I am well on my way!
The next use has been as a magnet board.
I have used them to jazz up other pieces I have created. I save even the smallest pieces and use them in ways that scrapbook paper would be used to make art.
And the latest way I have used one is as a tray to catch the birdseed that the birds drop over the edge of the feeder.