the scapula should always move along the scapular “plane” which really isn’t a flat plane but is curved because the scapula wraps and moves around the rib cage. it should not “wing” off the ribcage or be oriented incorrectly. see this video:

this post is bound to cause some controversy- there are still many coaches and PTs promoting incorrect scapular action especially through exercises that pinch the shoulder blades together or exercises like scapular pushups. even the crossover symmetry system, as good as it is, promotes this in their DVD (i use their cables but stop short of pinching the shoulder blades at the end).  but i’m a convert on this more recent information regarding the role of the scapula in stabilizing the shoulder.