I wrote in Markdown. I turned that into a microsoft word doc that I formatted then created the PDF. I used pandoc to create the EPUB, then calibre to make the MOBI from the EPUB. I tried to use pandoc to make the PDF but it did not go well, word was surprisingly easy to use for that. The cover art was created by a friend of mine from college. I used https://diybookcovers.com/3Dmockups/ to make the image on the landing page.