Robin Hansen's Favorite Mittens is a compilation of her two earlier books, Fox & Geese & Fences and Flying Geese and Partridge Feet. The two earlier books are out of print, and I don't have them. So, I can't speak to the benefits of owning the third book if you already have the other two.
The book features traditional mitten patterns from rural Maine and Canada. As you might expect, they tend to be very warm. There are a few patterns for wristers (fingerless gloves that can be worn under or instead of a mitten) and hats, as well.
It is perhaps wrong to call a book about traditional techniques innovative, but there are many methods described in this book that I haven't seen anywhere else. Patterns are also easy to follow and are offered in a table format - to allow you to choose your size.
There is enough background about the mittens, techniques and names, offered to allow the casual textile history enthusiast (like me) to feel enriched, but not enough to fatally bog down the pace of the book.
The book opens with a general instructions section that is thorough enough to allow the budding knitwear designer to leap off in their own direction - and be confident about the fit.
However, nearly 30 patterns are also written very clearly. The patterns are mostly mittens, but as I mentioned already, there are also hats and wristers. I dare say that the stitch patterns involved could also be turned into many different garments.
Let's just say that thrummed slippers are in at least one cold-footed person's future.
The back of the book includes suggestions for further reading and sources for yarns used in the book. Many of the yarn companies are still around.
Speaking of those particular yarn companies. If you haven't considered them before, please check out Peace Fleece. It's a great little yarn company in Maine and they make wonderful products. I used a dark blue worsted of theirs to make a wedding afghan for my twin sister 10 years ago and it still looks fantastic.