how to create subfolders in Mac OSx with a "preset"...?
Use the Services and .workflow with Automator to get subfolders into a new folder.
I use this so have folders ready when starting editing new videos.
Simple...
Here the links mentioned in the video:
https://github.com/mariuszostrowski/f...
Mariusz Ostrowski
who created the Workflow.
https://www.macworld.com/article/1163...
Kirk McElhearn
for some background on the services option.