Some silhouette exercises, numbered for your (and my) convenience. I like doing these because they're quick and helpful, letting you make easy decisions about posture and shape without putting in all the little details. I took a class with Brian Ralph in school and he really hammered home the value of silhouette drawing.
I think 3, 6, and 8 are my favorites so far, but let me know your thoughts. Also compare these to regular goblin silhouettes (here).