1. Portrait Drawing
Vincent van Gogh Dutch, La Mousmé, 1888 oil on canvas, 73.3 x 60.3 cm (28 7/8 x 23 3/4 in.) Chester Dale Collection

2. Facial Proportions
The blue line in the illustration shows the dimension of the head vertically, and the red lines show the dimension of the head horizontally. The head is basically an "egg shape". You can see the egg shape a little more clearly on a bald person!

3. Facial Structure
This illustration shows the basic oval shape of the head (red line). The purple shading is showing the basic structure of the entire head. An egg-shape, with a some shading around the nose, eyes and mouth.
Exercise 1

4. Setting up Guidelines
Here's how you align the features up on the head:
First, the vertical magenta line divides the face into two separate halves. Use this to keep each side of the face even and balanced.
The red line goes across the eye-line. The eye-line is right in the middle—between the top of the head and the bottom of the chin.
Halfway between the red line (eye line) and the bottom of the chin is the blue line—where the bottom of the nose is.
Then, a little less than halfway between the nose-line and the bottom of the chin is the mouth-line.
Also note the yellow lines that go up and down—they line up at the corners of the mouth, up to the pupil of the eye

5. Facial Width
The line of blue almond shapes going across the face represents "eye widths". Each blue almond shape represents the width of one of the eyes on the face. The red lines are there to make the division between each eye-width more obvious.
You will notice that there is an eye-width between the two eyes. And then there is almost another eye width between the edge of the eyes to the outside edge of the head. So, this means that the face is approx. 5 eye-widths across.

6. Drawing the Eye
Eyes are a very important and evocative feature of the face! People will notice any problems or flaws in your drawing of the eye, so special care needs to be taken.
The basic shape of the eye - an "almond" shape. The red line shows that there is an angle to the shape of the eye. The top of the eye has its widest point to the right, the bottom of the eye has its widest point more towards the center, or left. Exercise 2

7. Drawing the Nose
The nose is a feature that is often overlooked by portrait artists. But it shouldn't be! If you don't get the nose quite right, the whole portrait suffers. The drawing on the left shows the simple outline of the nose. Two lines for the length of the nose, the round "ball" at the tip of the nose, and the nostrils. The nose is made of these simple shapes.
The middle illustration shows the basic outline of the nose, with some shadow and rendering starting to show.
The illustration on the right shows a completely rendered nose. Notice how the strong "outline" on the light side of the nose is almost gone. Notice how the outlines for the nose are now indicated more with shadow, rather than harsh lines.
Exercise 3

8. Drawing the Mouth
Notice that the upper lip "dips in" (and therefore usually is darker, since it has more of a shadow). Notice how the lower lip comes out, which makes it lighter (more light on it). And notice how the corners of the mouth have more shadow. You will often want to make the corners of the mouth very dark.
Notice how there are 5 basic "sections" to the lips. Depending on how much of a "cupid's bow" the person has, you will emphasize these "sections" a little, or a lot. When you draw the mouth, be looking for these subtle (or not so subtle) "sections" to the lips.
Exercise 4

9. Drawing Hair
There are three things to pay attention to when you are drawing hair: the hair strands, the tones of hair, and the structure of the head that the hair is on.
Hair is shiny - it has highlights, and dark areas. The first thing you should do when you draw hair is to lay in the shadows and highlights with a broad loose pencil stroke. Don't put in any "dark dark" tones yet, just indicate the shadows and highlights. Draw the areas of light and dark as "strips" of tone.
Then, go in and draw in individual "hair strands" (but you don't have to draw in every hair!). Draw dark, sharp pencil strokes, to give the hair some crispness. But, still leave the highlights and mid-tone areas intact. Don't let them get too dark, or blend in too much with each other. These distinct variations of tone are what keeps the hair looking shiny.

10. Common Mistakes
DON'T draw an eye like this! So many things are wrong with it. Notice that the eyebrow is kind of close to the eye itself. Should it really be this way? Often, the eyebrow is higher up. Look at your model closely, and make sure that you get the eyebrow placed in the proper place.
The eye is too much like a football shape here. The eye should have more of an angular, asymmetrical almond shape.
There is no tear duct. People will notice its absence, if only subconsciously.
The thickness on the bottom lid is drawn badly. This area should be drawn with a delicate touch - if not, the eye will look uncomfortable. The hard line that goes all across the bottom lid is not flattering. The line underneath it (where the eyelashes are) just makes the whole bottom lid look ugly.
The eyelashes look too spikey, and are starting to resemble spider's legs. Creepy-looking.
The iris is not round. It has to be round! ROUND, I tell you! The pupil also is not round, and is not concentric with the iris.
Too much of the iris is showing. Usually there is a lot more of the iris concealed underneath the top eyelid.
Also, what are those wheel-spoke lines coming out from the pupil? There is no shading on the eye, eyelid, or anywhere. It makes the eye look flat.

11. Common Mistakes
DON'T draw the mouth like this! Notice how the lines are too harsh all around the mouth. The lines at the corners of the mouth, the chin, and underneath the nose. Too harsh, not necessary. There should be delicate and subtle rendering around the mouth, to show the structure and expression of the mouth.
The center line (that divides the top lip from the bottom lip) is too straight - this line is usually curved in at the middle.
The shading is simplistic and does not accurately represent the structure of the mouth and lips.

12. Common Mistakes
DON'T draw the nose like this! The lines are too dark and harsh on both sides of the nose. Put less shadow (if any) on the side of the face that is facing the light source. The shading is too dark and harsh. The nostrils are not shaded at all - and there should be some shading on the nostril that is in more shadow.

13. Exercise 1
MAKING AN EGG HEAD: As a prelude to working with an actual head, we'll learn about the relationships between light and dark by using an actual egg. Experimenting with an egg head has an advantage at the beginning of your study of the head and features: You can set it at any angle you choose - yet it won't move. To make an egg head, take an egg and make a hole in each end with a pin. Hold the egg over a bowl and blow into one end, and the inside will come out, leaving the empty shell. Rinse it out with clean water, handling it carefully. (When you begin to use your egg as a model to draw from, you'll find you can make it stand on end by using an empty pill bottle or bottle cap as a base.)
EXERCISE: (1) Hold the egg upright and draw a line with a fine marker or a pencil straight down the shell's center, top to bottom. Now draw a second line horizontally around the egg, halfway down and at right angles to the first line. on either side of the vertical line, draw eye ovals on the horizontal line - this is called the "eyeline".
(2) Add a second horizontal line just above the eye ovals. This will be the "eyebrow line". Now, not quite halfway down between the eyebrow line and the very bottom of the egg, make a mark for a nose, crossing the central vertical.
(3) Now try turning the egg a quarter turn to the right. You may need to add another vertical line from top to bottom halfway around the side where the ear would be. (4) Tilt the egg slightly forward and draw the eyeline halfway down at the SIDES of the oval, but rounding downward at the center. Place the eye ovals on this curved eyeline and add the eyebrow line following the curved eyeline.
Facial Structure

14. Exercise 2 A step-by-step diagram on how to draw the eye.
Draw the outline in first. Notice that the shape of the iris is round on the sides (it is a round circle) but its top is obscured by the upper eyelid, and a little bit of the bottom of the iris is obscured by the bottom of the eyelid.
After you get the shape correct, start to draw in the light outline of the lower eyelid thickness. Draw in the pupil (which is round) and indicate where the highlight on the eye will be.
Then start to add shading and detail. Keep the indication of the lower lid light and subtle. Make a few subtle lines to indicate the eyelashes. The upper lid will cast a gentle shadow on the eyeball, so add shading to indicate the roundness of the eyeball.
Drawing the Eye

15. Exercise 3 Drawing the Nose The nose, step-by-step:
First, sketch out the outline of the nose. You don't have to draw a dark line down both sides of the nose. Usually one side is more shadowed than the other.
Start to add a little shading to the side of the nose that is in shadow, and the bottom of the nose. Define the nostrils. Shade the nostril that is in shadow a little bit, but not as much as the rest of that side of the nose. The nostril sticks out a little bit, and gets more light on it.
Finish shading the nose. Suggest, through gentle shading, the "roundness" of the center (bulb) of the nose, and the roundness of the nostrils.
Drawing the Nose

16. Exercise 4 The mouth step-by-step: Sketch the outline of the lips.
"Block in" the shading of the lips, putting more shading on the top lip, and leaving a highlighted area in the middle of the bottom lip, and some highlighted areas on the upper rim of the top lip.
Add more shading and rendering. Don't forget the "ridge" around the lips, and the shading around the mouth that suggests its structure. Add the darkest accents of tone to the corners of the mouth.
Drawing the Mouth

17. Vocabulary
Render - To represent in a drawing or painting, especially in perspective. Also, to create an interpretation of another artist's work, perhaps in another form. Also, a coat of plaster, cement, or concrete which is applied to raw brick, stone, etc., or to apply such a coat.
Portrait - A work of art that represents a specific person, a group of people, or an animal. Portraits usually show what a person looks like as well as revealing something about the subject's personality. Portraits can be made of any sculptural material or in any two-dimensional medium. Portraiture is the field of portrait making and portraits in general.

18. Webography http://www.portrait-artist.org/face/structure.html