Ron Gilbert's (@grumpygamer@mastodon.gamedev.place) puzzle dependency charts might be of interest.

They're very useful for puzzle narratives to help with structure, particularly around visualizing the breadth of parallel tasks available to the player, and avoiding dead ends.

The open source godot game engine has a plugin for them by the excellent Nathan Hoad (@nathanhoad@mastodon.social).

I guess cyoa, particularly in pen and paper form, can be necessarily more linear and deliberately do feature dead ends, but could still be interesting.

Also, some interactive fiction software might be useful to aid planning, even if you weren't intending to make a videogame. Stuff like Twine.

I'm Adventure Game Studio all the way myself. Not because I think it's the superior tool necessarily, but it's got a very easy learning curve and it's versatile enough that you can get away with a lot of really cool things.

Huge Ink fangirl here for narrative design; works great for CYOAs.