Organising your mind
Humans minds are not very structured in a linear way. Many of us think in different nodes that might or might not be connected. One way to brainstorm, with the possibility to connect our thoughts easily, are mind maps.
Table of content
There are many mind map services and applications out there. Some of the one's I am using are MindNode on my Mac and iOS devices (free app with additional paid functions) and Whimsical (online service with free plan available).
Mind Map & Brainstorm Ideas
Whimsical: The Visual Workspace
One advantage with MindNode is that you can export your mind map as an outline into .rtf format or Microsoft Word.
What file formats can MindNode import & export?
Whimsical offers more possibilities to brainstorm with different options such as flowcharts and sticky notes.
If you prefer to write plain text but still want to connect your ideas, Obsidian is an excellent choice. If you want to know more about the app in general, check out the page Write Smarter on this site.
Obsidian can help you to connect your thinking. For an overview of how to do that, see the video of Nick Milo - Linking Your Thinking.