I'm starting off with Dungeon Year Design Journal by Pandion Games as my framework, and will adapt my approach as I go.

In that document things are summed up as: "When you're done, perhaps you'll have a massive interstellar spaceship, a new world to explore, a community of people and their relationships, a city, and yes, even a dungeon. Create anything you want."

Pandion Games also made the fun Banda's Grove.