It's hard to maintain posture when hunched over computers and phones all day. But, if you can improve it, you'll instantly look and feel better. For better posture keep a few things in mind.
First, stand up as tall as you can. A common trick is to pretend you have a string attached to the top of your head that is keeping you upright. Next, put your shoulder blades back as far as possible - yes, it may feel odd at first. Lastly, make note to lift your chin up and look straight ahead. Do this whenever you are sitting, walking, talking or doing just about anything. You'll have a poised posture and improved confidence in no time.