Not long ago I received an email from Paul. He is very enthusiastic about the Zettelkasten method. This method allows you to make your own database in which can you organize and collect your ideas, file your literature, connect different aspects and draw conclusions.
All the above is not always easy to do and you often tend to abandon lots of ideas, notes, doodles, open tabs or post-its. Marjolein offered me a while back some useful suggestions on how to make notes with Zettelkasten as a starting point. Notion is one of the tools you could use for this.
Paul suggested an extensive addition to all this with an article on the 20 best apps on how to make notes. Perhaps one or two could be useful for you.
In case you can really recommend one app or the other, please don’t hesitate to share this in the comments.