In each folder of my Zettelkasten I collect notes with similar characteristics.
Example:
Every note in the “3_Permanent Notes” folder is limited to one idea only (atomic note principle) and has a link to it’s source (simple rule).
The Obsidian forum is a great help learning from others. So it is reading books about Zettelkasten and PKMS. But it’s not easy to understand the different key terms from different sources. Here is my overview and classification for different types of notes with their synonyms and characteristics.
Figure: Zettelkasten Ontology Map visualising the simple rule “Always keep a link to the source”
A lot of detail, but sometimes it’s better to see the context on one page.