I use a tree-based note keeper called Keynote: https://github.com/dpradov/keynote-nf/releases
I use this for everything. I have a bunch of general categories like work, home, health, etc; I keep notes for every work project under its own category, house projects, car maintenance records, user accounts, password hints, operating system tweaks, etc.
I keep it backed up to my Google Drive so I can access it with my laptop away from home. I tried Evernote but I didn't like the interface. I really need something that works on Windows and Android seamlessly.
Visual mindmappers are a waste of space and time.* Brainstorm on paper or a whiteboard, then take hierarchical notes in something like Keynote NF.
Edit: I meant just from a usability standpoint, mind mappers end up with a lot of wasted visual space. Look at the example screenshot.
Edit 2: A waste for me, that is. If it works for you, that's great! But try Keynote or some other hierarchical note-keeper for a little bit to see how you like it.
Consider KeyNote NF:
(1) View Here: https://sourceforge.net/projects/keynote-newfeat/
(2) Direct, Portable Download Here: https://github.com/dpradov/keynote-nf/files/1132060/keynote\_1.7.9.Beta9\_Test.2.zip
I started using it approximately 18 years ago. You can store 1000's of small notes in a tree structure, and it features (a): a mode that automatically indexes the system clipboard, and (b) the ability to mount a folder of text files as a 'virtual node'; you can then edit the files directly from interaction with the node.
I'm a user of an incredibly useful application called Keynote-Nf Is a personal information manager with a tree structure, like evernote. I use it for storing information and organizing my job. I'm looking for a discussion space where discuss how to use it for planning and GTD, maybe a subreddit ! :) KEYNOTE NF IS FREE AND OPEN SOURCE
KeyNote NF is note taking software that is more like older versions of OneNote than, say Evernote. It's pretty good for keeping campaign notes together. NOT to be confused with the Apple PowerPoint replacement.
https://github.com/dpradov/keynote-nf
I've used it for years.