Standard Faces...
Okay so to begin with I will demonstrate the "standard" way of drawing more real or American comic book style faces.
1. Begin by drawing a circle. It helps to make a few "circles" in the same place, it's very hard to draw a perfect circle without going around a few times. (Note that if you change this beginning circle shape you can change the way that the face looks - making it fatter etc. for different character types).
2. Next add a cross shape over the circle. This should be halfway down and halfway across the circle (centered).This will be a guide for where the nose and mouth go
3. Now add a "V" shape to the bottom as shown.
4. Now you have to add the side shapes to the V. Try to keep these pretty even.
5. Sketching the neck in...
6. Placing the features: Note where the ears and nose are in relation to eyes. Look at photos of people if you've never really noticed this (or yourself in a mirror). Eye size and spacing is pretty flexible depending on what type of character you are drawing. Real people have space between their eyes equal to about the width of one eye. Anyway, you can see the placement of the features in relation to the basic shape of the face.
7. Okay! Using the shape as a guide I've actually drawn the face for my "Standard" guy.
8. I could leave it as in step 7, but it looks pretty blocky and stiff eh? So I added expression and made a more relaxed drawing based on my original one.
Moving on to the standard "girl" face. It follows the same steps as for the guy, but a girl's face is a little thinner and more delicate. And of course she should have more eyelashes and all that stuff! (Note this COULD also be a very "pretty" guy).
Elves and Other Faces...
So now you're wondering how to make those cute anime elf faces? Or fantasy faces? For this type of thing I "relax" a lot more and use less guidelines.
In the examples of the "Cute Elf" shown here you can see I dropped the square "superman" jaw look and instead gave her more of the just "V" shape.
In steps 6, 7, and 8 I show a few ways to shape the face by curving parts of it in and out. The shape of the Jaw as a lot to do with how your character looks - so make sure not to give all your characters the same shape face!
In the other faces example shown here I show how I draw many faces - a more relaxed "doodling" method. I draw the basic circle but I just keep making relaxed circle like shapes until a face appears to me. I tend to place the eyes following the bottom curve of my initial circle - especially when I am drawing evil characters, elves and Gremlins/Goblins.
I hope these ideas of how you can draw faces help. There are, of course, many ways of drawing them and these are just a few ideas that have worked for me. (Also I know this only shows one view of the face - from the front - I will try to add more about drawing profiles and other views sometime soon!).