This book is all about how to alter flat patterns. You learn about everything from style lines and dart manipulation to creating collars and puffed sleeves. I will warn you that this book does not have any sewing help. It shows you how to create a design with a flat pattern but not how to sew it. I love looking at all the design inspiration. It's so fun to just look at the pictures, and then realize you can make all of those with a little bit of flat pattern work.
My favorite page in Patternmaking for Fashion Design* is the page with all the math done for circles. It gives you all the measurements (length, radius, etc) for a quarter circle, a half circle, a three-quarter circle, and a half circle. I often use this for skirts and dresses, but with the flared sleeve trend right now this does all the work for making your own bell sleeve! Then you can attach the flared piece to your tried-and-true sleeve pattern without having to buy a new pattern!
I would recommend this book, Patternmaking for Fashion Design*, to anyone who wants to create their own pattern, anyone who wants to really create their own styles from a basic pattern sloper, or anyone who does a lot of pattern hacking for their kids. If you draft your own sloper to fit your body shape, you can use this book to create any style you can think of from your personal sloper.