Here's a list of things tutorials could be made for:
Manually cleaving sectors
Making water surfaces animated/ adding .mats in general
Making doors/elevators/forcefields activated by switches
Making locked doors that can be opened with a key
Making a secret area
Adding ambient sounds to an area (e.g. cantina music from a ghost_pos)
Making new templates
Adding custom files into JKEdit and creating a new template for it
Making a pit of doom...
Creating domed ceilings
Adding dark jedi enemies (cog has to be added manually)
Tinting sectors a certain color
Making a conveyor belt
This is just a simple list of common things new editors would want to learn. They're all very simple things to do. Some things hardly take any time at all to make, so the videos could go pretty fast.