Insertion - In storyboard, there is a need for speed and quick read so Insertions are a vital tool - This is maybe not anatomically correct all the time, but again those wedges around the joints add dimensionality and depth by overlapping the masses.

Draw Through Shape -Animation screencaps are great to study, but imho storyboards are better because of the nature of their crudeness. -we can see some of the "scaffolding" of the drawing and thinking process that evaporates in the inking process of 2d animation production

Same Shape - we are all simple creatures and one can spend whole life trying to learn anatomy and different muscle groups. - but for some, what is important is the story so simplification and shortcuts like this are vital for speed and efficiency

Open Close Pose - those are vital poses for storyboarding to showing the acting of the character - contrast between open a close poses creates visual interest.

Flipping the Masses -sometimes there is no place for extreme acting. -but we still can add some interest by shifting the weight of parts in this case head and torso tilt. -also twisting figures is another way to add dimensionality to your drawing!