If you have a phone with a pen (e.g., Galaxy Note), sketching is rather fun. FWIW, I use Adobe Sketch, for which I get a license through work. Not quite creating but also not quite passive consuming: Anki or other apps for learning (when I am in a good period, downtime becomes opportunities for buffing up geography and music).

Agreed with this ! The Apple Pencil w an ipad and Adobe sketch is endless fun, and a really new way for me to interact w the world around me!

Any practical system would probably be progressive. This would give a "soft" ceiling to wealth, and maybe actually favor small startups versus large well-established companies.

If you are already an Emacs user, try org-roam. It encourages to divide the note writing into short chunks that can be easily linked together (as in Roam), but you get all the goodies of the org-mode ecosystem, including:

- For programming, you can use org-babel to write short snippets that you can then run directly in your note (a la IPython notebook, but for pretty much any language). Super-useful if you are learning a new programming language. Alternatively, you can add an org link to specific files/functions inside a code base.

- To promote recall by generating flashcards directly from your notes, add anki-editor to sync with Anki, or org-drill. With Anki you can do reviews from your phone.

- To quickly incorporate a screenshots, use M-x org-download-screenshot (useful while taking notes off an online video or presentation)

- To refer to sources: file links (e.g., PDFs) and web links work out of the box; for academic papers, use org-ref and BibTeX files; if you are on macOS, you can also link to emails (useful to keep track of projects); I am still figuring out the synchronizations with PDF annotations.

- If you need math equations, use LaTeX snippets inside your org file and org-fragtog to automatically render them inside your notes (without having to export/compile the entire file as LaTeX).

- Use ag or pt to search through all your notes using fuzzy searching.

Notes are just text files all in the same directory, so you can use git/Dropbox/Google Drive to sync. If you use Dropbox and have an Android phone you can use Orgzly to edit your notes. The most useful feature is that from any app you can "Share" with Orgzly, and add it to one of your notes (I use it to add notes related to podcasts).

I concur with other commenters about making your note taking as frictionless as possible (I have Emacs opened all the time, so org-roam was an easy choice for me)