Many mistakes start with the incorrect positioning of the objects that form the skull
To correctly make a head I will demonstrate the key points of both front and profile.
In both cases the face starts with a circle divided in half and all the spaces that remain are divided in the same way.
The first line that we see represents the separation of the cheeks and the eye sockets ,In the next step we visualize the light blue lines that are linked to form the ears, nose and chin.
Finally, the yellow line represents the location of the eyelids and the beginning of the lips.
At making a profile, we can see the initial shape as a shooting target, the center always forms the base of the ear and the beginning of the chin.
We draw an eye first to learn to visualize an eye without an eyelid, since it is easier to choose the shape of the eye, and visualize the correct position of the iris and pupil (something that people tend to ignore a lot).
To create the eyelid space is divided into four points, two at the ends to define the length of the eye and one up and down, which will mark the weight of the eyelid.
A trick to visualize the position of the eyes is to draw an eye in the center of both since this is the measure of the space between them.
Another very useful TIP when creating characters, is to use an eyelid style to reinforce the main feature of the character.
The ear is very simple to draw, its enough to design the outer shape and then use straight lines to match the gaps that lead to the eardrum.
Contrary to the case of the ears, the complicated part of the nose is when we add the depth effect, especially in the lower part.
But fragmenting the nose in this way is much easier to visualize the shadow effects, it is just a matter of practice and visualization.
The lips are divided into a cross in which its intersection decides the center of it, you just have to make the shape of a heart and at its bottom the shape of a drop.
In this last fragment one of the most important topics to be addressed is the "Same Face Syndrome"
It happens commonly because people who draw, usually use the same formula for all their characters, the best example for this is Yamil in his cartoon called
"My imagination and me."
When a character makes an expression or speaks, the elasticity of the jaw is indispensable
also an important factor to generate more realism in the expression
is the positioning of the eyebrows.