Per the request of Erin in the comments, here are some examples of the kind of the marginal minimaps and annotations I was making in my prep to run Deep Carbon Observatory.

Also, you should use Claytonian’s version of the dungeon map, which I unfortunately didn’t have access to at the time: http://killitwithfirerpg.blogspot.jp/2017/07/deep-carbon-observatory-map-fan-map.html.