I don’t really know how to help, but I guess I always run through a sort of check list when I’m sketching characters that I learned in animation/storyboarding;
1) can you tell who the character is by their silhouette alone?
2) can you tell what the character is doing by their silhouette alone?
3) can you tell what the character is feeling by their silhouette alone?
This doesn’t apply to all pictures (you can have the feeling/motive of the character solely relying on the face, as with a close up, or a change of expression with two identical poses) but it’s a really good exercise to get your body language clear and keep the ‘acting’ of an image to the point. Try to keep limbs held away from the body so you can ‘read’ them, and remember you can use the hands in communicating emotion too.