Create a digital design in your favorite vector editor; I use Adobe Illustrator. Keep it simple because the thickness of the drill bit will limit the amount of detail you the wood will retain. Also, consider which part of the image you want to be inked and transferred, remembering that the negative space is the space that has to be milled away.
I used MakerCAM (makercam.com) to generate the toolpaths for a Shapeoko from the SVG file. In my case I needed to make a pocket around the entire design because I wanted the drill to be raised to take the ink. Make sure to double check all the settings and make sure they match your machine and material (especially step-down, feed rate and drill bit size).
I used a cheap roller and ink from a linoleum block printing kit from a local art store. Apply a generous amount of ink using the roller; you don’t need to roll over many times, as that actually removes ink rather than adds ink. Then simply press your design onto any medium you like: I used paper and cardboard