A handy tool for both designing, reading, and running an adventure is a simple, diagrammatic flowchart. The flowchart shows the main encounter locations, meaning all major skill challenges as well as any potential combat encounters, linked together to show all the possible paths that the dungeoneers can take. A diagram that is very simplistic is easy to run and prepare for, but can run the risk of feeling like a railroad. Likewise, an overly complicated flowchart can give the dungeoneers plenty of freedom, but makes the Dungeon Master's job more difficult. The flowchart informs the adventure's author just how much complexity they are putting into the adventure and guides the Dungoen Master with an easy to follow reference for where their dungeoneers are headed to next.
Just for kicks, I put together these images showing the flow diagrams for Madness at Gardmore Abbey, SND-01: Revenge of the Iron Lich, and C1: Crucible of the Gods. The most interesting thing I found out of this little exercise is that it clearly illustrates just how much complexity and nuance is put into the two Fourthcore adventures, which represent only one gaming session each.