Mind maps can be hand drawn or you can use a software tool.
Include lists, sketches or photos of locations.
Add ideas that you have of props, people, themes.
This is a reflective, log-book like post, not formal, with a lot of freedom to explain why you rejected an idea / reformulated an idea / developed an idea.
Title idea?
I should have enough information by the end of the post to understand the treatment that you are pitching me.