My own system (which is an entirely physical one) is designed around this principle; each step is designed to make me engage with my own recorded thoughts in a different way:
- Every note gets written on an A5 sheet of cardstock, with a unique slug written in large print at the top of the card. The bottom ~(1/3) of the card is reserved for cross-references.
- After writing a note, I look through the file box of existing notes for 2-3 related ones; these become the initial cross-references and are notated on both cards.
- The new card gets photocopied, and the original placed in the file box, ordered alphabetically by the slug/title.
- The copy gets turned into a flashcard by blacking out the title and put in a Leitner box (a physical spaced-repetition system)