It looks like some of the best angel investors are in a network of startup founders. I wonder if someone angel invested only in 2+ time founders would returns be different.
Really a personal mix of analog and digital; I will try to explain a bit in detail, hope this gives an idea.
So I use Bullet Journal (analog notebooks) for perusal work and Notion/Org Mode for office work; Notion for non IP work and Org mode for IP work. My org mode is not in cloud anywhere; only on my disk. All my planning and to-dos go somewhere in here.
I follow this directory layout convention in my home directory:
So for everything I am working through, say a book 'Realtime Rendering' under 'Graphics' subject area, I make a dir 'Books/realtime-rendering' directory with 'mind-map' directory which contains all mind-maps scanned from my analog mind map notebook where I make the mind maps with pen and paper. This also contains the exported Anki flash deck for that book.
After making this a habit, I have found that I have become selective about what to work through; I take my time to find out as there is good but worth-it effort to make flash cards and mind maps for long term memory augmentation. Even if I am not very regular (only about 50-60% a week) to review my cards, I am way better off now than before putting this system in place.