A few people have told me that it's better to do the mapping of the zone in general and then the eventing, but it seems I can't create another map until I finish the eventing of the one I'm currently working on.
I've noticed that more videos on YouTube have these segmented bookmark things in the videos themselves. It's nice being able to jump to parts of a video you want, and to have them all clearly labelled.
I've always dreaded planning for my games so I just didn't plan at all. That... didn't work out after all.
Turns out it can be kind of fun if you keep the scope small and don't take it way too seriously.