I do this in three ways:
- Note title
For notes about a common subject, I start the note title with that subject, so similar notes will live next to each other in the file list.
Eg: “Notes should have clear titles”; “Notes should contain one atomic, thought”; “Notes should link to other notes whenever possible”
- Internal Links
When writing a note, I try to identify related concepts and link to those other notes.
Eg: in the note, “Notes should link to other notes whenever possible”, I might mention that “links should reference discrete thoughts, and this is possible because [[Notes should contain one, atomic thought]]”.
- Folders
For notes about an area of focus with multiple topics, then I’ll create a new folder and move related notes there. Kind of like a separate, working slipbox/commonplace book as I wrangle with a subject.
In a couple cases, I’ve “finished” my wrangling and moved the notes back to may main folder and deleted the folders.
In a couple of others, I’ve been wrangling of and on for about a year and still have them in the folder.
Bonus, because of Obsidian’s search and linking, the separated notes aren’t really separated from everything else.