This book contains some useful tips, but basically it's unlikely to tell you much you don't alredy know, or can't easily work out for your self with a little applied common sense. It is way over priced - it is a very small, thin book, and most of the book is not about the topic described in the title. It's cleverly marketed, and the cover photo is certainly very eye catching: what an excellent photography! But it's a pity the cleverness of the marketing doesn't follow through into similar cleverness of the content. The offer of a "Free course" advertised on the cover seems to have expired, now, and you have to pay by the look of it. I stumbled upon this book by mistake, while searching for books on sleep, but I feel sure there must be more helpful books out there on this topic.