I prepare summary notes for the books I find particularly valuable and well-written.  I  generally go through these books twice, the first time on Audio or Kindle and the second time on Kindle.  With the second read I highlight text to show the argument and to capture particularly good phrases.  I copy my  highlights to Word, tidy them and then add before the highlighted material a paragraph to summarise the book, around a dozen bullet points to set out the book’s main points, my comments on the book, and sometimes links to useful podcasts and websites.  I then turn the word document into a blog post.