I have been using the playbook here for the past half-year or so. It’s made a big difference not in how I communicate, but in how I understand communication problems. There isn’t much to the book. You don’t need to read the whole thing, you can basically find summaries online and use those. The book is padded out because people won’t pay much for short booklets.
Something that I took from this book is to try and do the communication from the listener’s side—extract the four steps from people who are assaulting you with demands.
This meshes surprisingly well with other books on the subject, like Getting to Yes, which is about negotiation.