First, I write out a 3-4 sentence campaign description to get the overall plot of the campaign, then generate a three act structure with 3-4 sentence act descriptions.
Then I make an adventure plot table to create high-level overviews of adventures that will take place in the acts. This lets me keep a goal in mind while not spending much time building anything specific.
I use the overviews to create the actual adventures in a nearly just-in-time method. Usually Iām working one adventure ahead, although sometimes Iāll work on the adventure theyāre currently running, just depends on how much free time I have. I like these adventures to take anywhere from 2-3 sessions, so I try to plan for that. I start out with a 3 Step Plan for whatever the big bad of the adventure is, and then I think about what the players need to do to disrupt each step of the plan. Example from the current adventure my players are on, which Iām still working on:
| Step |
Plan |
| Start: |
A Rakshasa, Rabar is in QāBarra trying to free Masrivik and needs a sacrifice |
| Step 1: |
Blackscale Lizardfolk are patrolling the Adder River to kidnap travelers |
| Step 2: |
Kidnapped travelers are taken to HakaāTorvhak |
| Step 3: |
A sacrificial ritual is conducted, led by Rabar |
| End: |
Rhashaak awakens HakaāTorvhak and releases its destruction |
These adventures are mostly just layered 5 room dungeons, unless I want a dungeon crawl or skill challenge or whatever. I use this 5 room dungeon approach to build a session story structure, but in-session I actually mostly improv, but doing all the previous work lets me improv towards a specific goal.
Hope that helps!