I used to write notes in pencil at the top of the pages (down the bottom and down the sides in the columns too if I ran out of space) in my course books. They were definitions and phonetics for unknown vocab, so that I could do quick reviews at the start of each study session. For example I'd do 10 minutes of revision flicking through a bunch of pages just referring to the new/unfamiliar vocab that I had written in pencil at the top of my pages. I'd then mark that page and do the same next study session, continuing from where I left off last time. A kind of SRS I guess. After the 10 minutes I'd do 50 minutes or whatever of progression through the coursebook from wherever I was up to in terms of working through the content of the book (i.e. not the pencil written notes).
Then I discovered SRS applications and stopped writing in my books. Unusual vocab, unfamiliar/new words and grammar notes were made. I made too many cards. Too much detail usually, and it took me too long to figure out over months or a couple of years, the best methods for creating cards. Then I got sick of them.
I started taking notes in a notebook. Then I got sick of that.
Nowadays I'm back to simply revising sections of coursebooks. I can't be bothered with SRS, notes, or writing in workbooks. It's faster to move on, and faster to just review the actual content of the course books, or whatever material i'm using, as opposed to writing it all out. It's also probably that given I'm at least intermediate if not approaching advanced in French, that note taking and SRS seems to be required less. Things make more sense, phrases and vocab have connections to now that didn't exist before. They're not isolated odd concepts anymore, even the unknowns. Even completely unusual words and phrases at least sound French, as opposed to just a sound mass.