My rule of thumb is usually this: if I can sketch a tiny character’s face in a couple of seconds with a handful of lines and it’s still recognizable, it’s a good face.
Comic artists have to quickly produce lots of high-quality art, so tricky faces aren’t best for business. But let’s forget that reason for a sec.
In drawing, it’s important to focus on the general form of shapes rather than details. Art schools make students draw these weird choppy heads to help them focus on the abstract planes, before they can draw realistic detailed portraits:
Focusing on the broader task before defining the details goes for anything, really. In writing, you outline the entire plot first, and then write each chapter. Smaller parts organically follow the main narrative, so everything feels harmonic instead of disjointed and confused.
So if you successfully define the general shapes, you can observe how exactly they correlate with each other. I’ve posted sketches of two of my characters who have pretty basic face structures. I tried to make them expressive without losing those correlations to the point of making the characters unrecognizable. I actually made some notes for myself after this little exercise:
Now, if you focus on faces and forget about details like strands of hair, eyelashes, monolids etc, you can see what the most important features are shaped like and where they are placed:
Even if I quickly and sloppily sketch them, while keeping those proportions in mind, you can still tell it’s them:
I’m not necessarily talking about character diversity here, btw. Even if your characters look mostly same-ish, that common face structure can have its own unique proportions. Case in point: V’s face unintentionally formed from Dolly’s face (aka CalArts face) from my previous work. Awkward.
Anyway, if I know the proportions of my heads, I can rotate them all I want:
I have two things to keep in mind here: the placement of the features that I figured out previously and the general anatomical rules of what a head looks like from different angles. It’s not always easy to balance them out with each other! For example, when V looks down, the general rules say that the nose gets closer to the mouth, but the big distance between her nose and her mouth is pretty much her defining characteristic, and I risk losing the similarity.
However, I don’t think that the character looking slightly off is a big sin. If it actually crosses the line, I usually just experiment with those proportions, until the face looks recognizeable and functional enough for me. Or better yet, start the sketch from the scratch. Don’t make your doodles suffer countless corrections.
If you have problems with the correct rotation of the head in 3d space, I don’t know what can help you aside from practice, practice, practice.
John K offers a pretty interesting exercise in drawing toys of cartoon characters from different angles to better grasp the volume. Those choppy art school heads or skull studies are also hella helpful. I wish we did them when I was taking classes as a kid :c
Again, one of the most common beginner mistakes is focusing on details, rather than general shapes, so if you decide to practice on your friend or some 3d model of a head, please remember about it. It’s hard at first, but worth trying.