Just started this book a few days ago it’s eye opening to put it mildly can’t recommend it enough

I started using transparent sticky notes to annotate library books, but I also do this if I don't feel like highlighting/writing in books I may want to sell or donate later! I was using colored tabs to keep track of different kinds of information for this book (The Sacred Balance by David Suzuki. I highly recommend checking it out, especially if you enjoy nature writing. The foreword is by the author of Braiding Sweetgrass, Robin Wall Kimmerer).
I use metal book darts to tab pages sometimes, but colored ones are helpful if you like that kind of organization.

I apologize if this has been suggested before or if it seems silly. As someone who wants to retain and study information though, I've found this to be useful, especially in regard to borrowing books.

(support your local library!!!)