Many if not most books on relationships out there are not good. Sometimes the author had a spot of luck and generalises. Sometimes it’s just stuffed with common knowledge, or advice meant to make people feel in control. Of course, most of them are also horribly gendered, and subscribe to differences between men and women at ridiculous levels, and/or assume relationships to be heterosexual.
Rewriting the Rules by Meg-John Barker was way better than that. I found it well-structured, and coming from excellent principles. It moves through a set of topics, starting from dealing with oneself, going through different points of relationships with others, such as starting out, having sex, separating, dealing with conflict, and ends on a couple of very good practical observations. All chapters discuss cultural rules we may apply without thinking (about gender, sex, behaviour in general, partnerships vs friendships, etc), and how they can be harmful and beneficial. This discussion is both very practical and very differentiated, which makes for a nice change compared with most other books of this type. I’d recommend it without hesitation for people looking to read and think a bit about relationships and friendships.