I use this a lot when storyboarding a first pass of a sequence. Placing hands in the right, most appealing position can be tricky. In order to create a clear silhouette for the hands, I often draw them “floating in the air”. Then, using my general knowledge of anatomy, I just “fill in the arms”. This way I can create a much more expressive and clear pose than if I was just radiating out of the torso. That’s when structure and anatomy can get in the way of a clear message. And hands carry a lot of meaning, so I want to make them as clear as possible for my audience to see them.