One philosophy I have about writing technical material is that I want to condense the material as much as possible, to the point where I want people who use yellow highlighters to mark most of what I write. I am one of those people who use yellow highlighters, and I look for that property in books that I read.
This isn’t necessarily true for blog posts that I write, because for these I usually write them pretty fast. But for books, I take the time to review them and look for this quality. This follows the design mantra, “reduce, reduce, reduce.”