another way to become aware of your body, posture and
everything that goes into good breathing, singing, etc
is the Alexander Method. I have several friends who
teach this and it helps you be in touch with the most
efficient way to hold, move, etc. it is often taught to
actors, singers, and others. it also is helpful for
improving your body sense and can prevent injuries in
situations like working, playing and physical activities.
Alexander Technique
Ergonomics article