As an end-of-year review exercise, I time-traveled back to the 7th grade and compare-and-contrast'ed what I did then with what I do now.
The biggest difference is that in 9th grade my biology teacher ( Hi Mrs. Allard! ) talked about how she took notes. At the time, it passed over my head and only later did I realize that it was not a standard well-known system (ie. not Cornell, mind-mapping, outlining, etc.).... She carried a clipboard to class with plain mimeograph/copier/printer paper, recorded all her notes throughout the day on that, then after classes transcribed her notes/learnings into final notes that she would then file into a three-ring binder.
Much later, Inbox Zero became a thing and its echos of note-taking made me rethink everything. Granted, smartphones are ubiquitous now, and so to make a credible 7th grade system, some de-Internetization is required. That said, without further ado...
There are three components:
Throughout the day, dump all notes and todos into the notebook. At the end of day, clean up and rationalize all the notes while transcribing them into the journal, either by expanding previous entries or creating new ones (one per sheet).
Any todos undone are then filed into the 3x5 cards with one card per day. Finally, rip the used pages out of the notebook, and write the list of todos for tomorrow onto the blank now-first page of the notebook.
Leave the journal and stack of todos at home. Losing them would be a huge loss, whereas losing the notebook is a small problem easily remedied. Ideally, the journal suffices for a semester's worth of learning, and goes onto the shelf at the end of the semester. You will find yourself periodically flipping through them, and reconsidering old learnings.
It can be argued that Notebook Zero is a sub-class of the Cornell method. However, two large effects are at work here that are absent in the latter: 1) the active recall of whether today's notes impact prior notes causes those memories to be used every time you file notes, and 2) knowing that something is going into "The Book" makes you worry about its correctness and ferret out any oddities by reading further and pestering people to clarify understanding.