5. Your Neck
The only postural imbalance possible in the neck is a head that protrudes forward. For this you can stretch your neck by putting your ear to the shoulder and holding. Do each side for about thirty seconds.
You can also stretch the back of the neck by putting your ear to your shoulder and then looking down towards your shoe. Hold for 30 seconds on each side. Being aware of the problem will help you change your posture and pull your chin closer to your head.
To do this, just pretend that a chick you are definitely not into, is trying to come in for a smooch and you really dont want to kiss her. I bet you would pull your chin in pretty quick.