A wise old fellow gave me some sound advice the other day. I'm sure among some better coaches it's common knowledge, but to a novice like me, the effects are amazing.
The conversation was about the importance of having good posture in your stance. Specifically, NOT hunching or rounding your shoulders when you shand. If you do, your shoulders with work overtime to support your arms, and you with end up arm punching due to poor hip rotation with your punches. With you back straight and your chest out, your torso supports your arms and your hips are loose to whip around with the punches.
I have started doing this and I noticed and immediate and amazing difference!
(and is there a breathing benefit to standing this way? Less pressure on the diaphram?)