Expressions are a vital piece of information that can tell you how a person is feeling, what they want to emphasize, and how they want you to react to them in return. A great deal of information and experience can be gleaned from observing people. Your best examples will be people who are relaxed and comfortable sharing expressions with you. Translating these details to paper takes a matter of perspective and a few tips. Once you know the basics, the rest of the drawing is just practice.

Have these tools handy:
  Practice pad of paper (this can be anything from printer paper to professional sketching paper)
  Pencils
  An eraser
  Music, ambient noise, scented candles, or silence—whatever helps you stay relaxed and focused.

Set yourself up at a place where you will be comfortable and that has a hard, flat surface, such as a table or a desk. Also make sure to give yourself adequate lighting. Once you're comfortable, you're ready to begin.

Step 1: Looking at the Whole

Take a moment to examine the whole picture. You can use yourself or a willing friend to practice with. A simple smile has a lot of detail that is not limited to the mouth. The cheeks upturn slightly, the eyes may not be facing the camera, eyebrows may be raised, and the nose may be wrinkled.

Step 2: Partition

Divide the face into quadrants. The face is symmetrical vertically and asymmetrical horizontally.

Make your horizontal partition travel through the center of the eyes. Two lines—one above and one below the eye—will tell you how tall to make the eyes.

Additionally, you may draw a line to indicate where the eyebrows would be in a neutral, resting position, where the tip of the nose falls, and where the mouth would rest beneath the nose.

Step 3: Doodle Some Simple Expressions

Take a moment and doodle a couple of expressions that you know. These may be from emoticons, cartoon character’s faces, or from other pictures and professional drawings. You may notice that expressions can be divided into components. Eyebrows, mouths, and eyes take on different shapes depending on the expression. For example, surprise includes raised, arched eyebrows, a mouth that is agape, and widened eyes.

Experiment a little by mixing different shapes of eyes, eyebrows, and mouths to see how this works.

Step 4: Draw the Head

On your sketching paper, freehand draw an oval.
Note: Do not press down hard on your pencil during this step, and don’t panic if you mess up. Leave the lines! Don’t erase anything yet!

When you have a nice oval shape, darken the line you want to keep and erase all other extraneous sketches.

Now, add in the lines that partition the face. These should reflect what you drew on the print picture of your chosen real-life example.

Step 5: Put It Together

If you just draw in the eyebrows and mouth like you see them in the doodles, you could potentially end up with the beginnings of a cartoon character. Go ahead. Try it.

The pictures below are examples of a basic head with one raised eye brow and smirk. The eyes are a little more realistic than a doodle as is the nose, but that is up to personal taste. I left in the partition lines for you to see how these parts go together. Want to draw something a little more realistic? Let’s look at the components that make up a more realistic face.

Step 6: The Eye

Tackle the eye by drawing a horizontal line. The vertical line will pass through the center of the eye, where the iris and pupil sit. To draw the eye looking left or right, draw the line slightly curvilinear either to the left or right side.

Lightly sketch the outline of the eye.
Note: You can use the print picture of the real-life example to practice sketching the eye.

Next, draw in the iris and the outline of the pupil, and then add the lines that make up the lids. (People’s eyes are variable, so sometimes these lines aren’t clearly defined.)

At this point, you may decide to darken in the pupil, add a few lashes, shade a little, erase the guidelines, and be done with the eye. That’s fine. There's plenty of time for complicated eyes later.

Take a moment and look at what you've drawn. Does it resemble the eye from your sample? If it does, great! Keep practicing drawing eyes this way. If it does not, don't be discouraged! Instead of erasing and starting again, simply begin again next it, using that eye as a guide of what to do differently.

Step 7: The Eyebrow

There are a variety of different thicknesses of eyebrows. Take a look at a couple of different eyebrows. Notice how each of the individual hairs tends to bend toward the edges of the face. We can replicate this using a simple trick.

Take your pencil and draw short, light strokes opposite of the direction of the side the eyebrow is from (for right eyebrows, this is toward the left side).

Apply this technique to an expression. When we doodled, we used a single line to represent the eyebrow, but now we know that the eyebrow is a little more detailed than that. If it helps, first outline the shape of the eyebrow.

We eventually want to avoid having guide lines, so once you’re comfortable with a certain eyebrow shape, try drawing one without the guide lines.

Step 8: The Mouth

A mouth can be drawn in three simple steps. The most important is the line that defines the upper lip and thus defines the smile, frown, or whatever you decide to draw.

Go back to the doodles and pick a mouth you want to draw. Sketch it.

Once you have your mouth outlined, draw two curvilinear lines. The top lip will be convex compared to the mouth you drew, and the bottom lip will be concave. The top lip will have a little dip at the center.

Step 9: Finishing Up

Practice everything. Practice a lot.

Redraw the oval shape, the guidelines, and then start sketching your face. Your first attempt may be the worst you have ever done or it may be the best. Don’t give up because it does get better with time and practice!

Here is a review of important points to remember:

1.) Relax. Have fun. Learning can be both frustrating and rewarding but more the latter if taken with patience and an open mind. If you find that you're getting frustrated, take a break.
2.) Don’t press hard. If you have to go back and erase later, you’ll find that dark lines don’t go away as easily.
3.) Don’t erase so much. Erasing is tempting to do, but sometimes those errant lines may come in handy. If you erase only when you’re sure you need to, you may find that the process of drawing will go a lot smoother.
4.) Practice. Doodle. Experiment.
5.) Keep your old drawings. They may certainly upset you now, especially if they aren’t up to your standards, but you can really learn from them. Occasionally, I pull out my older drawings and compare them to my newer ones. Seeing the improvement is an effective confidence booster.