Source: 📖 How to Take Smart Notes
Luhmann (creator of the Zettelkasten method) would write notes with his mind on the other notes already within the slip box—he would write new notes thinking about the dialogues already occurring inside to identify what kind of connections can be made to existing lines of thought.
Literature notes were succinct but written with great care and accuracy. The aim is to capture an idea as concisely as possible without losing any detail. Always use your own words and never copy & paste. Be extremely selective with quotes. The aim in writing these is both to capture ideas and understanding them to begin with.
Literature notes can be very brief as they link directly to the text they were taken from.
Links can then be made to other notes, subsequent or related in some way.