Here are some essential tips on how to draw heads:

1. Keep in mind the angle from which you are looking at the head. Whether you draw from life or from a photograph, the perspective will have a major influence on the apparent tilt of the head. For this simple demo, I will use a frontal view of the model.

2. Measure the ratio between the width and the length of the head, either with your finger, a pencil, or some other tool. Transfer that ratio to your painting surface; in other words, place marks where you want the top and bottom of the head, measure that distance, and then use the ratio to place marks on either side to indicate the maximum width. Make sure you do this correctly, as this is a crucial step in getting the structure of the head right.

Note: The purpose of this initial process is to “frame” with a volume of space within which you will create your drawing. Therefore, when measuring the ratio, get the distance between the longest and widest points of the skull.
As you fill in the details of the head, you will then crop inwards (if, for example, the hair is slicked down) or outwards from the frame (e.g. if the subject wears their hair in an afro). You want to focus on the skull (not on the hair), so measure from the top of the skull to the chin, not from the hairline.

3. Once you position the eyes, the rest of the features should be fairly easy to locate. Your next important feature is the nose. The base of the nose is usually half way between the top of eyebrow and the chin, but this varies from person to person.

4. If the human head is relaxed with the mouth closed, the lip line of the mouth is generally halfway between the base of the nose and the chin.

5. The top of the ear is usually aligned with the eye level and the bottom of the ear is aligned with the bottom of the nose, but again, this varies from person to person.
6. The average distance from the hairline to the peak of the eyebrows is the same as the distance from the top of the eyebrow to the base of the nose, but this ratio fluctuates greatly (depending, for example, on whether the person has any hair at all).

7. Once you have the vertical spacing of these features in place, then check their horizontal alignment using either a plumb line, a ruler, or simply a straight pencil. Check the distance between the two eyes, where the corners of the lips begin in relationship to the eyes, the width of the nose in relation to the eyes and mouth, how far the outer corners of both eyes are from edge of the skull, etc.

Now that you have the knowledge you need of the anatomy of the human head and the techniques for getting the features right, it is time to practice your skills.
Draw any human heads you can lay your hands on—in books, magazines, photographs, or live models. First, get the correct skull shape clear in your mind, and then follow the sequence I used in this tutorial. You will be amazed at your progress in learning how to draw heads!