Hello Kokoro Reflections,
First want to say everything you make is great. I have been buying your sets for a long time, and watched your art improve. I appreciate your work and look forward to watching you improve further!
I would like to suggest a few tileset themes. An arena (I would prefer Roman Era, but whatever you think would help the most people), a steampunk theme (city), and maybe a themed cities and town series? I hope you continue and do twelve legendary temples and the library idea suggested sounds good, I personally can make do taking pieces of your old sets to create a library if need be but sounds like there is demand. Whatever you do, I will continue to support your work and thank you!