I found this a while back on deviantArt and I just recently found it again on my computer. It’s a great challenge for artists to create different facial expressions for you characters.
You can make a sheet for each of your characters, draw their expressions, and keep it on hand to refer to when drawing your comics. It sure helps when you are under a deadline. It also has the added benefit of making you figure out these important facial features of your characters so they don’t look lifeless on the page.
Here is the link to the talented artist Nancey Lorenz at deviantArt…
And the link for her deviation 25 Essential Expressions Challenge
Here is the file for you to look at, but please go to her DA page and download it there so she gets the hits on her page.