How to read books effectively

I've noticed I struggle to remember even the outline of the non-fiction books I read after some time so I decided to implement a better system for information storage and retention. Here's the gist of it, I thought it might be useful for someone:

a) Reading for 30-45 minutes a day = 30 pages / day = 600 pages a month = 1.5book a month = 18 books a year. You are guaranteed to read at least 18 books a year.

b) Four note taking techniques for reading books:
1. Writing down ideas and concepts inspired by reading. Some books do not present too many new concepts but mainly just put you mind into a different frame - for example Simon Sinek’s books. Out of this different frame you can spawn new ideas or draw inspirations worth writing down.
2. Writing down summaries of content. Usually used for difficult texts or first book in a new area of study to work through the content. I used it often when studying for hard exams. Preferably with colourful pens and highlighters with nice paper to make it more fun :)
3. Tree of ideas. It’s a mindmap that only goes from left to right with a tree of relationships between concepts, examples, stories, ideas, argument, counter-arguments. I might switch to graphs in the future.
4. Anki flashcards. Needed for putting content into long-term memory so that you always have it “on hand” when needed to make some decision etc. Eg. content from deep work when planning a week.

c) Some books, within the same cluster, can be read for entertainment, outside of daily regiment. It is especially useful for books that have more fluff, are more popsciency, less content dense. Eg. Peak by Ericcson vs Deep Work or So Good They Can’t Ignore You.