Custom field sets can be attached to posts based on their selected category. When an author is editing a new post, the custom fields will appear after the author selects a category.
This idea was posted in How should we implement our custom content types in WP? on 2016-09-19 by 
I found this technique to be slightly buggy because under certain conditions the custom fields would not appear. However, since this is just for admins, the conditions are easy to avoid and one can just to a page reload, so it is a viable option.