These dominoes were a one-off I made during a game of The Socks and Puppets Game.
To make these, I started by buying a set of (cheap) blank dominoes. I believe they are made by a company called Tobar as part of a domino run. It's quite hard to find nice blank dominoes. Next, I spent some time with a bit of paper, designing the joins, and figuring out where to put corners in. (Unlike regular dominoes, the images on these dominoes join up at the edge of the dominoes. You want some of the dominoes to turn corners so the game doesn't end up being really long.)
Once I had plans and dominoes, I sketched the designs straight onto the dominoes themselves with a mechanical pencil, and then added the ink with Staedtler pigment liners. Colour was added with Stabilo point88 markers. I boxed the whole set up in a little wooden box to finish off.