I love to use a paper notebook for fast notes, random thoughts, and to capture tasks (something similar to a GTD inbox). With it, I use a small system of symbols (some degree of similarity with the bullet journal method).

The only issue with paper is the edition. My solution has been to use a compact, slim ring binder with a notebook-like feel. If required, you can move sheets to reorganize content, move the most important ones to another place, etc. Until now, the best alternative that I have found is the Kokuyo Campus Smart Ring Binder.