@jupe this is pithy and inaccurate but a book is just a poem where every line is a chapter
start by thinking about how you want your ideas to be structured and how you might put them together in a way which “rhymes” and “resonates”. get a solid structure that you feel confident in (but don't force yourself to follow it too closely). figure out what the structure is “saying” and why it's important
then just fill it out with enough words to make it work
@Lady thank you!