“The most basic element of design is the line; it can be horizontal, vertical, curved, bold, implied, or diagonal.”
Horizontal and vertical lines – stability, quiet, restfulness – they are usually first to attract attention.
Diagonal Lines- action, violence energy – movement where there isn’t any. Character that is unstable- a “malfunction”.
Curved lines – different meanings depending on their size and shape – Sharp curves suggest turbulence. Soft curves- imply a sensual or soothing quality – harmony. The S-curve can be a main subject or a framing element.
Jagged Lines- combo of multiple lines – horizontal and vertical – diagonal and curved – convey a sense of restlessness and agressiveness.
source: Understanding Storyboarding.