An interesting topic for me would be how artists deal with really large scenes. Asset management.
How to prepare assets (how to model and texture for Terragen), does and dont`s of working in large scenes.
Managing node networks, etc.
Something like dissecting and examining a scene of the challenges that were done here perhaps.
Also, of course, the blue nodes.
How to use blue nodes in your daily work, for example. Simple networks that make your life easier.
Something like adding colours or masks with blue nodes instead of using the Merge, Surface or other red nodes.
How to integrate this stuff in different scenes.
Last but not least - how to recreate a real life scenery from scratch.
It is one thing to hit the Seed button and connect arbitrary nodes or trying to create the form and silhouette from a photograph or something.
Hope, you can make it happen.
CHeers, Klaus