So now I'm making a "practice" dungeon, loosely following the official My First Dungeon tutorial put out by the CS devs. I've got one cell completed with lighting, clutter, enemies, pathing etc. Now that I've gone through all the steps for one cell, I want to add at least one more with a boss room, then create the exterior worldspace linkage to integrate it into the game properly.
It's been an interesting process, and I've expanded my knowledge of the CS a bit. Level design is its own skillset and I'm definitely a rank amateur. Lighting has been one of the trickiest things to get right, even more so than normal interiors as there are more considerations for gameplay. Since I'm deliberately copying the vanilla devs' style closely, the dungeon itself is going to be pretty generic and not worth a mod release. But I'll have some experience I can put into making a really cool dungeon for the market! It's a useless hobby, but I'm enjoying myself.