I’ve noticed that my posture is pretty bad. Not horrible mind you, but I certainly don’t “walk tall” – I look kinda mopey and/or sad. And, in my defense, lately I have been mopey and sad BUT I’d rather still look my best so I decided that my best posture corrector would be to follow some interesting advice I heard on the radio.
A guest was saying that the most flattering way to walk with beauty and grace is to pretend that there is a string pulling your head up as you walk; to stretch out your neck and be as tall as you can. I have to admit, when I do that, I do look much better 
And I’d also say that I FEEL better too. So, give it a try; imagine that imaginary string pulling on the top of your head and see if it doesn’t make you feel better too!