I’d like to recommend a lovely little book: Generous Movement, written by Alexandra and Roger Pierce and published in 1991. It’s available for about $11 online, and used copies can be found for even less. 
 
The Pierces are (I believe they’re retired) both academics: she in music, he in drama. Roger Pierce trained as a Rolfer and worked with Judith Aston in the early days when she was developing Rolf Movement Education, the ideas that later evolved into the movement aspect of Aston-Patterning. The point of view found in Generous Movement, whatever it owes to Aston and others, is well-digested and gracefully articulated. Knowing that movement disciplines like Alexander Technique and Feldenkrais have found their most secure home in the world of the performing arts, it’s easy to imagine how much the Pierces employed these principles in their teaching careers.
 
The book’s subtitle is A Practical Guide to Balance in Action, and it delivers the goods. Most of the book is about common everyday activities: sitting, standing, walking, reaching, lifting. It’s pleasant and rewarding to browse, but a close reading of the book will reveal many profundities. I would recommend it to anyone, from curious client to experienced professional. In my opinion, no general book about posture and movement can touch it. 
 
The Pierces also authored a longer book, Expressive Movement, which contains a fuller exposition of more or less the same ideas. It’s also available online and in a Kindle version as well.