Mapping
A good texture, often needs a good mapping.
Here I talk about the mapping of head textures.
First, proportions.
No matter what you draw, You must follow correct proportions.
Like in reality or any manga face or body drawing, you must have the correct proportions, else it will be a junk.
Human realistic drawings and manga are alike,
You must take the distance you are drawing the facial features first.
lets start with the eyes.
On the eyes, you are free on the size, just don't mess with the general face size.
In the placement,
it is one eye in between the eyes, almost one eye to the ear, take a good look where the eye is going to be.
now with the rest of the face, it is one nose, under the eyes, not too distant from the eye, but might have a good distance sometimes,
the mouth is right below the nose, just a little space under.
About the size, the nose is free size, just not too big.
The mouth is from one of the eye to the other, no matter where in the eye,
Just in the middle of them.
Going to the sides, the ears comes on the seide of the eyes, can be half eye of distance or a bit more.
The proportions of the ear is like real human ears.
From the most top of the eye to the end of the nose.
The jawline is optional,
You can place it from the ear, passing under the mouth close to the last circle in the texture template.
it can be a good option to make the head more mature.
The hair could go above the eyes, letting an empty space for the forehead.
Some types of general mapping:
the first is a low face, it can work sometimes, but makes the whole head so childish and big looking.
the second is normal mapping with the chin, totally correct, I cant see anything wrong.
the third is just a small face and how it maps, it si a big mistake, just like a too big face, maps really bad.
And the other the notmal mapping without the chin.
This explain a lot about mapping differences.
Make your own mapping, and make sure to make it look good and proportional.