Knowledge needs to be organized for easy recollection, and link ideas together.
Collect knowledge as short "ideas", with references and links between each other, and some categorization. Process reading notes and articles into usable knowledge, actually understanding what was there to make it useful. Condense for readability.
Organize using tags. Link notes together, explaining why. This part is crucial to dig deeper into a topic and see parallels into other fields. The linkage already initiated to be done during the collection.
Keep references to support ideas, and save them.
Think long term, notably for storage, tooling, and reference saving.
Knowledge management is a way to increase signal, therefore reducing entropy
Zettelkasten — How One German Scholar Was So Freakishly Productive describes a paper systen that more or less represents a mind map. Ideas are organized in free pages sorted in folders. They are linked together through references.
Christian Tietze on why using categories is not a good idea.
Take smart notes is a note taking methodology. Notable the author posted a description on Quora:
It is easy to confuse this technique with the way hyperlinks or tags work on the Internet. But this is not a personal Wiki. It is not about storing knowledge, but about developing thoughts across a wide range of topics and building up long strings of interconnected notes that can easily be turned into manuscripts. We all know that we should elaborate on the things we read and make connections between heterogeneous ideas (as this is basically the only reliable and proven way to learn anything) [...]. A good note-taking system forces us to do what we know is right. The Zettelkasten does exactly that.
~ Sönke Ahrens, Author of the book "How to Take Smart Notes"