One of the more interesting features of the writing process in Using Zettelkasten to write a paper is located in step 5: the use of the slip-box in a bottom-up fashion to discover those ideas you’re already developing, rather than predetermining those areas you may be interested in and attempting to sort notes into those categories.
This is also related to Matuschak’s advice to Prefer associative ontologies to hierarchical taxonomies in his Evergreen notes concept.
This shift means that structure is emergent and therefore does not need to known in advance. In my (admittedly limited) experience, this has expressed itself most in reducing the activation energy I need to record my thoughts into a note. By removing the need to know in advance where I might place a note, I’m free just to open an editor and record the thought.