Reading should not just be a one-way transfer of knowledge where the reader passively receives information.
Instead, reading should be an active process where the reader is underlining, synthesising, asking questions, and relating concepts to other circumstances.
The reader should have “conversations” with books to maximise learning and retention, and optimise the reader’s ability to apply new knowledge.
These ideas above apply mostly to those who read to learn. Reading for entertainment only is different, and needn’t follow these guidelines.