If there is one thing I pay close attention to is POSTURE.
Well, thank you Mom (and dance); she (and dance) have been big advocates since I was five!
A good posture almost immediately makes you appear three notches more confident; standout in the crowd, not to mention few inches taller (if thats what you are after).
A great posture and stride also makes you happier, psychologically.
Always be mindful of your posture during daily chores; walking, washing dishes, working on your computer.
Exercising may help improve your posture – try yoga, taichi or any type of exercises that focuses on body awareness.
Maintain a healthy weight – extra weight may cause problems for your pelvis and spine; which may result in back pain which in turn may hurt your posture.
Bottom line is, walk and sit erect, you will not regret and people will never forget.