Watch Out For Inverted Curves

One of the main things an animation artist needs is to be able to take what sketches come before and keep the guts of them, while fixing the actual mistakes. The more you understand the tools, the easier that becomes.
One thing I watch for is too many inverted curves that break up the form or line action.
I've exaggerated the inverted curve at the front of George's torso to show what I mean.
You want the silhouette of the form to flow around the curved line of action, not eat into it.

It's not very pronounced in this drawing, but there are some modern cartoon styles that are made up of too many inverted curves and it gets hard to read the overall image, because it breaks up each part. If I see some online, I'll add them to the post.