When teaching Pilates, I am always telling clients to keep their shoulders away from their ears. Raised shoulders is a sign of serious tension in the neck and upper back and over time it will create pain. Not only that but it wastes energy and can make surrounding areas not function correctly. Pilates clients aren't the only folks with tense necks and raised shoulders. I see this posture all the time when people are working out with weights, biking and running.
In an effort to keep the shoulders down, people tend to tense their necks even more – as if the sheer weight of their neck will calm the busy shoulder joint. Or people tend to grab in their lats or arm pits, which also increases neck tension and interferes with free movement of the arms.
To effectively relax your shoulders, you need to focus on your shoulder blades (scapula) sliding down your back. The muscle that anchors the blades is the bottom part of the trapezius muscle. You also want to feel your collar bone (clavicle) widening and the scapula sliding slightly toward one another. The end effect is an open chest with relaxed shoulders and neck. Nothing should feel pinched or gripped. Imagine the scapula is a slippery bar of soap sliding up and down the back. Try it next time you do bicep curls, sit in freeway traffic or ride your bike.