When I moved into my apartment, all the units in my building had door numbers that were made of ceramic. They were fine, but I wanted a door sign that would 1) fit over my door tile non-destructively, and 2) feel a little more specific to me.
I was reading a book on the history of the California Academy of Sciences, a museum that I remember visiting as a kid and then many more times as an adult. This picture of an engineer in front of a planetarium projection system he built from scratch stood out to me; during the Cold War, the East Germany-based Zeiss company was unavailable to sell products to Americans, which forced scientists to get creative.
Using Cermark spray and my Glowforge, I tried etching the image onto steel. The etching failed partway through, but I liked the look overall.
After it came out of the Glowforge, I ran it under water to remove the chalky white Cermark.
I then cut the metal and hammered it around a piece of wood designed to fit precisely around the apartment number sign I had outside my door.