These images show the techniques described "in action". I have not done much with these images as "on the wall" art, but have made a number of mug patterns with them.
The first step is to write the program. It should not be thought that all programs work. Many of them produce quite boring results. What you see here are the "survivor" algorithms that produce "interesting" results most of the time. A good bit of tinkering with the various parameters such as random walk step size is required for best results.
When a program produces mostly interesting results, one runs multiple runs and then selects the few that are "best". Some might object "Isn't that making art too mechanical?" I would demur. Most art is selective. A photographer walking in the wilderness doesn't just shoot any old scene. The randomness of nature presents him with many scenes that are boring, repititious, or cluttery. He goes on until he finds that "just right" view (a tiny subset of all he has seen). Here I went on among random views until eye-brain-experience-history combined to judge an image "just right". I have little doubt that others would often have made different choices.
You can see all of John's mug designs on the Zazzle site by clicking here. mugs