Cyanotype is a really simple process that is easy to do from home, which I have definitely taken advantage of. At its core, the process involves simple chemistry - ammonium ferric citrate and potassium ferricyanide - mixed with distilled water. The cyanotype process was invented in 1842 by astronomer John Herschel as a way to copy his notes. Because of the iron salts in the chemistry, the resulting image is a deep Prussian blue color. This process is actually where blueprints came from (hence the term 'blue print'). Soon after his discovery, Herschel told his friend Anna Atkins about this. As a botanist, Atkins had previously sketched her plant specimens, but this new method afforded her an accuracy she could not get in her sketches. In 1843 she self-published a photographically illustrated book titled Photographs of British Algae: Cyanotype Impressions.
The beauty of this process is that it can be applied to a wide variety of surfaces. In my own work, I have printed on a variety of different papers, as well as coffee filters, paper towels, and cotton handkerchiefs. Cyanotypes can be easily toned, too, using tea, coffee, and wine. This is tricky, though, because it involves a knowledge of bleaching and a keen eye. You can submerge your print in one of these solutions to get a split-toned print that is both blue and brown, or you can submerge your print in a bleaching agent (photographic developer, trisodium phosphate, etc.) and then submerge it in your toning agent. The tannic nature of both tea and red wine work really well to tone images. The trick is knowing when to pull your print from the bleaching solution, and how long to leave it in the toning solution to achieve your desired results.