I love to world build, and have created many worlds over the years. I hate to always run back to my Kaidan setting of Japanese Horror (PFRPG), but it's the only setting that was fully developed and published in some kind of complete form. Because much of the design mindset in the project was trying fix the many issues I've found in the original Oriental Adventures, and while focusing on key cultural elements of the setting, I sought for nuance of detail, rather than comprehensiveness of every possible element. I focused on a dozen key aspects and delved deeply for each, rather than trying cover every possible aspect. Putting aside the magic, folklore and cosmic horror aspects, Kaidan was as close to an analog historical Japan that I could achieve. I think I nailed the realism and verismilitude. Now I use Kaidan is the bar I set for all my other setting designs.