Below is an image from George Bridgman whose book, in my opinion, is a great starting point for cartooning students who want to kick it up a notch.
A disclaimer is in order here, however: note that Bridgman, in his anatomical schematics, exaggerates in order to help you notice - feel - the figure's contours and that they are not to be taken as literal document. People don't look like Bridgman's figures. But Bridgman's figures look alive.
We also discussed clothing folds. Accuracy in dropping in the lines representing the folds in a character's attire is important in making the action in an overall comic panel feel right.
*Life drawing groups around Seattle:
There is also an excellent session every Wednesday from 5:00pm - 7:00pm at
Artist & Craftsman Supply in The University District, hosted by Jamie Bollenbach.
Email Jamie at firstname.lastname@example.org