Hold, but not still: using moving holds
Since the Golden Age of traditional animation in the previous century, animators know that regardless of the action performed by our characters, they must feel alive to our audience. When a character reaches the end of one action, it shouldn't remain completely still. When it happens, it looks like something went wrong—is he dead? Frozen? Is the TV broken?
To avoid that, we must add a slightly modified and carefully built pose after the hold so the character keeps moving and "alive". This is specially true in CG animation, where the animation is on Ones (meaning that each new frame brings a new "drawing") by default. In traditional 2D animation, where the number of drawings per second of footage is normally reduced, this principle is relevant but not always so crucial.
The animation principles are often related, so we generally find and use moving holds along with the principles of Follow Through, Anticipation, Slow In, and Slow Out. Thus, we shouldn...