I like to collect Casio watches, and have done stamps of some of my favorites.
These stamps depict the Casio F-91W, perhaps the most famous Casio watch of all, and the LF-20W which is a newer model that has a very interesting look with a digital recreation of an analog clock display. There are some notable mistakes in these stamps, including an extra button on the F-91W (which I removed from the final version of the stamp) and the missing date on the LF-20W (which I determined was too small to fit in the space provided for it). Still, I think they turned out pretty well considering the fine details.