I am in a similar situation and haven’t found the best way yet either. What I can recommend

• reading/watching a summary of the book to get the gist of it before reading
• listening to it and taking notes while you listen to it
• reading the actual book (digital or paper) and take notes the good old way
• use an app like Obsidian that allows you to link your notes from different books and create a network of ideas and concept

The last one is the one I’m not fully doing yet but it’s a really fascinating concept. Here’s an intro but there’s a ton on YouTube too.

https://www.keepproductive.com/blog/obsidian-beginners-guide