Pick a reliable anchor
Before exploring a new branch, identify a nearby landmark you can recognize both in the atlas and in the game. A save point or an unmistakable room shape makes a better anchor than an enemy that may move.
Look at the space between the anchor and your target. Room outlines help you estimate the direction of travel; they do not encode a validated walkable route. Verify doors and exits as you go.
Work through nearby branches
As an exploration strategy, check one nearby branch at a time rather than crossing the region for every visible marker. This keeps the mental map manageable and makes it easier to notice where a route stops.
When you cannot reach a location, distinguish an unseen entrance from an ability gate or a story condition. The atlas does not currently validate those requirements, so do not assume that an icon alone means you can collect an item now.
Revisit with a specific question
After a new ability or a story change, revisit a blocked branch with a concrete question: does the new action solve the obstacle you saw? Check that question in the game rather than treating every previously closed route as open.
Use a direct marker link or a normal browser bookmark to keep the relevant map page nearby. These are navigation aids, not a completion checklist. This method is general planning advice, not a tested speedrun or a guaranteed completion route.