#1. Face
As a prerequisite to this tutorial, you need an art program that supports layers, several sheets of paper and a lightbox, or tracing paper. This tutorial is meant to be agnostic to whatever method you are using, so you shall have to determine how to go about accomplishing layering.
The goal of the tutorials will be to teach a method to draw consistent images. Drawing by these methods will also allow you to draw faster. And by changing the proportions to whatever looks best to you, will allow you to develop your own style and, again, keep it consistent from drawing to drawing. It will also allow you to arbitrarily draw your characters from any angle.
To start off, one of the simplest things to draw is a face from the side. Drawing side views is actually the easiest, since you don't need to worry about symmetry. And the face is easy since it can be formed from a basic circle.
So first, create a new layer to draw on, and choose a color that is relatively light to draw with. Then draw a circle. It's not very important that it's perfectly round. And it doesn't need to be very clean.
Draw a horizontal line across the middle of the circle, but slightly below the center. As a general rule, the lower you draw this line, the younger the resulting character will appear.
Now, from one side where the horizontal line means the circle, draw a line straight down until it goes past the bottom of the circle a ways.
Then, from the middle of the circle, draw a line extending down and curving to the end of your last line. You should start curving it about as you exit the circle.
Your picture should look something like this:
Now, you draw a horizontal line midway down the front of the "face". This is where the base of the nose will end up. It is also where the bottom of the ear is.
Next draw a second horizontal line halfway between the last line and the end of the chin. This is where the base of the bottom lip should end up.
Create an eyebrow ridge just above the first horizontal line:
Now draw in the curvy bits:
And more curvy parts:
The top of the base of the ear starts from the same height as the center of the eye. And the hairline has an bump at the temple, towards the eyebrow.
In reality, rather than using a perfect circle, as we did at the begining, a slightly longer than taller shape is more realistic, but this is something to experiment with. The top of the head, for a more realistic character, should only be about 1/3rd to 1/2 the height of the brow over the hairline.
Our next step is to create a new layer to draw on.
On the new layer, we trace the rough drawing, trying to make some fixes as we do so, and adding some detail:
Having used a lighter color to draw with earlier, you don't have to worry about getting confused about which layer you're drawing on. And since we are drawing on a new layer, we can erase and correct lines without destroying the rough (sometimes you want to refer back to it, add more, or restart from it.)
Now we create another new layer and, again, with a light color draw hair:
There's not very many hints to give on drawing hair. You'll just have to practice, I guess. Realistic characters have their hair raise somewhere from a half a centimeter to a few centimeters off of the scalp. Anime characters generally have at least three to five centimeters.
And on a new layer we trace in some better lines, and make some corrections.
If we were going to color in the picture, usually we would want to leave the hair and the body lines on separate layers. But we won't be handling coloring yet. So we'll erase the scalp and any other places hidden by hair. We'll also get rid of the two rough layers. (You're best to just turn the rough layers to "not-shown", rather than deleting them.)
That gets us to this picture:
Now something to realise, is that as you work on a picture, your brain adjusts to see it as you mean it to be. So the way it looks to you, almost definitely doesn't look like how it will look to others.
Thus we flip the picture horizontally, and change the brightness of the layer so that it's grey instead of black (or just not use black lines on the previous steps....)
Probably, several things will immediately pop out at you as looking wrong. Yes, those really are all wrong. Record them in your brain now, very quickly, trying to figure out what is wrong about them.
Create a new layer, trace, making all the fixes that you noticed that needed to be made.
Repeat as much as needed. Flip horizontally. Flip vertically. Rotate 90 degrees. Etc. Make sure the picture looks correct from every angle. Create new layers, and fix errors.
As you get better, you will need to create fewer layers. But in general, you are safest to trace and fix, than you are to erase and redraw until you are satisfied that you know better.
And we end up with a picture like this:
Not the best picture ever.
But frankly, no picture which perfectly follows "the method" will end up looking very natural. They'll tend to look slightly flat and the characters will look tense. The picture also doesn't include any perspective, which is most of what is making it look flat.
As you get better, though, "the method" becomes a more fluid process and more liberties are taken. But being able to do it when needed, is what saves you when something isn't coming naturally, or if you want to try something that's beyond what you're capable of. And if you can draw a face with all the proportions right, then you can spend more time focussing on drawing hair without having to worry about the basic stuff.