Here are some keychains I made for my last employer. I ordered dog tag blanks anodized in red off the internet, went to a TechShop, made a jig to hold 20 of them, and laser-engraved the company logo on them. There were several variants, but this is my favorite:
Another variant with the logo inside a circle is shown below.
I left the instructions for making more with the next intern. Everyone at the office seemed to like them!