I think most people don't draw as expressively as they can. They don't push their poses and expressions to the point that they could and ambiguous drawing is the result. We all know that one of the hardest parts about drawing is crafting an image where anyone that looks at it can tell exactly what the characters are thinking and feeling. It's not easy, and like all the other posts in this series, that's why I'm bringing it up.
Sometimes I think people restrain their drawings because they want their drawings to look "pretty", and they're afraid that pushing the expressions too far will make for an "ugly" drawing.
To me, nothing could be further than the truth. I really love drawing pushed expressions, in fact, without that, I don't think drawing would be much fun. My favorite drawings of mine are the ones that have the most caricatured expressions.
Drawing expressively doesn't mean giving every drawing over-the-top broad wacky expressions, it just means that whatever the feelings and attitude of the character you're drawing, every element of their body (their face, their posture, etc.) reflects what they're feeling, and their attitude is very clear to whoever looks at the drawing. But the expressions should be appropriate; subtle for a subtle expression and pushed further for a more extreme expression.
Maybe another reason that expressiveness gets lost is that people are trying to draw "realistically" and they think only "cartoony" drawings are expressive. But real people can actually be pretty expressive. Also, we're not trying to recreate realism, every drawing is a caricature of reality on some level and every piece of art we create should be making a statement, right? Isn't that what makes it "art"? Besides, photography (and our own eyes) are great at capturing realism. Recording the world on paper exactly as we see it seems like a silly reason to draw.
It's possible that some comic books may have had a bit of a negative influence on expressive drawings. Sometimes comic book drawing is really technically good but without a lot of pushed expressions. I think sometimes artists that gravitate towards comics get really interested in drawing anatomy, vehicles, environments and dynamic angles but acting and emotions on the character's faces seem to be a low priority. I've seen really great looking comics that are drawn well but you can only tell what the characters are feeling by reading their dialogue balloons.
Of course, there are also plenty of great comic book artists who draw "realistically" and dynamically but also with great expressions that totally communicate to the viewer.
Will Eisner - a real master of finding the balance between drama, realism and caricature.
Jordi Bernet
There are a lot of other great comic artists who are good at this, I know. Alex Toth and Joe Kubert are also artists that can draw realistically, dramatically and also expressively.
Some other examples of expressive drawing:
Andre Franquin
Chuck Jones
Bill Peet
Quentin Blake
Ronald Searle
Sorry, these aren't the greatest examples, and I know I always return to the same artists over and over again as examples - I'm always pressed for time in scanning and posting. I'll try to broaden my examples in the future.
As always, look to real people and real actors to inspire you in finding great expressions.
It's always educational to see an actress who can remain attractive and appealing while being expressive. Two actresses who do a great job playing quirky characters with unique and odd expressions and pull it off in an appealing way:
Natalie Portman in "Garden State". She did a great job of using her face to show the oddball nature of her character but doing it in a really charming way.
When you think of the acting style Natalie used in the "Star Wars" movies it becomes even more apparent that her expressiveness in "Garden State" was a choice because it fit the character. In the "Star Wars" movies her character was a leader who was royalty and had to always appear strong and in charge, and always formal in all of her relationships. I point this out to illustrate that her odd and quirky expressions in "Garden State" were a conscious choice and not just her default acting style. It's a good illustration of the point that different characters have different levels of caricature that are appropriate to their personality and environment.
Gillian Jacobs in "Community"
More Community screencaps can be found at the Fishstick Theatre.
She has a great face and on the show she seems to always have a bit of a tweaked expression on her character's face even when she's just sitting and listening to another character talk. Her expressions are never symmetrical...always a bit off-kilter, which fits perfectly with her quirky character Britta.
A quirky, oddball character has a certain range and type of expressions that are appropriate for that character but wouldn't be right for other types of characters. And if all your characters have tweaky, weird expressions, then they don't seem quirky, they just become your style of expression because they don't have straighter, more subtle expressions to contrast with. So find the right range and type of expression for each character and each project. Again, push yourself - don't draw the same stock faces and gestures over and over. Study, observe and find new ones!
Drawing expressively is a lot like drawing appealingly, in that I've never heard someone say "Oh, that guy draws too appealingly" or "that guy draws too expressively". You can never have enough of those things; they both make drawings great.