In this Quick Tip I will be showing some useful guidelines you can follow to create the base of a head with facial features, following that up with quick tips on how to shape the facial features to create an expression/show emotion!
Step 1: Head Base
We will start by creating a base shape of the head before focusing on the expressions.
Start by drawing out a simple head shape, an oval for the skull, two ears, a neck and the start of the shoulder. Once you've got a shape that pleases you, we will start placing in the grid that will help us place the facial features. Now draw a vertical line that separates the face in half and make sure either size are about the same width. If one side is obviously wider than the other, adjust them until you are satisfied. We'll continue by drawing the eye line and the nose line. For the eye line, simply draw a straight line (Line Segment Tool (\) or Pen Tool (P)) from one top of the ear to the other. For the nose line, draw a straight line from one bottom edge of an ear, to the other. To define the height of the brow line, cut the section between the eye line and top of the skull into three. Only keep the line closest to the eye line and remember it to be your brow line. For the mouth line (that line will define the center/opening of the lips), cut the section beneath the nose line and above the chin in half, draw the line and remember it to be your mouth line.
Step 2: Features Base
The nose is the one that will help us with all the other facial features. Using the nose line, shape out the nose you want; Narrow, wide, sharp, round, etc. The width of the nostrils is a great way to determine where the inner corners of the eye should begin and where the top lip should start to curl down. And when you cut that width in half, you have a great reference for the temples (they are located on the eye line, started beside the top of each ear).
With the temples created, you'll also know where the outer corners of your eyes are located; so, with the inner and outer corners determined, you can shape out the eyes. For the mouth you want to make sure to draw the upper lip on top of the mouth line and the bottom lip beneath the mouth line. Finally, for the eyebrows, make sure to have them slightly bowed and that the line is slightly longer both on the inside and outside of the eyes. I then cleaned up the base with the Brush Tool (B), color black, Stroke Weight 0.3pt and the round brush in Illustrator's default brush panel.
Step 3: Smile
Much like the eyebrows, you want to draw a simple bowed line, the corners going upwards, to define the center line of the mouth and then shape the top and bottom lips to that line. While the eye shape doesn't change, adding one or two small lines on the outer corners to hint to subtle laugh wrinkles will add to the expression, since when you smile, your cheeks push up.
Step 4: Grin
Here you want to use the smile expression for a base. To make the mouth show some teeth, only move the bottom lip down and draw a new center line that defines the top of the bottom lip. In the newly created gap, draw some small straight lines for the teeth. Make the crinkles beside the eyes more prominent and even add a small bowed line beneath each eye to show the top of the cheeks pushing up.
Step 5: Surprise
All facial features move upwards and become rounder/wider. The brows arch up, like trying to shoot its way up into the hairline and because they do, you want to slightly lift the nose up a bit since the nose moves along with the eyebrows. The eyes are almost completely circular with the add on of the inner corners of the eyes. The mouth is the most expressive feature in this expression. You want to make the mouth less wide, but taller. It helps to create an oval for the mouth opening and then draw the lips around that oval (teeth inside the oval).
Step 6: Sarcastic
The eyebrows do most of the work in this expression, but there are some subtle things happening in the mouth and nose as well. Using the smile expression as base, reshape the eyebrows first. You can simply use one eyebrow of the surprise expression, since it goes up just as high. Whereas the other frowns downwards. You want to keep the outer corner about the same height as the smile eyebrow, but really push the inner corner down towards the inner corner of the eye. On the same side you have the surprise eyebrow, tilt the nostrils on that side subtly upwards. As for the mouth, use the original center line for the smile expression, and tilt it up on the same side as the surprise eyebrow. Adjust the upper and bottom lip to the newly directed center line!
Step 7: Disgust
Use the sarcastic expression as base for the nose wrinkle. Both for the center line of the mouth and the eyebrows, you want them to be as straight as possible. Create a prominent frown between the eyebrows, since they are essentially pushing together in reality and make sure the eyebrows push down onto the top line of the eye, hugging one another tightly. As for the mouth, the bottom lip speaks for itself, whereas the top lip, to really define the expression 'disgust', curl only one side (doesn't matter which) of the mouth upwards.
Tip: If you mix the sarcastic eyebrows with the disgust mouth, you get the expression: Unimpressed.
Step 8: Laugh
For the laugh expression we will use the smile expression as a base. Since the mouth opens further than it has so far, we're going to move the jawline down and at the same time, move the bottom lip down with it while keep the top lip right where it is. If you're not sure how far down you should move the jaw, use the length between the bottom edge of the nose and the start of the upper lip as reference. The top line of the bottom lip you can draw by followed the cheek lines. Much like the smile and the grin, you want the cheeks to be prominently apparent as they push up, but to add more to that effect, we want to make the eyes more slitted, as though squinting. To do this, select the bottom line of the eye, flip it horizontally, and adjust it back to the top eye! There, you've got squinted eyes! We also want to make the eyebrows less neutral by moving the inner corners closer to the bridge of the nose while curving the outer corners upwards as they originally did.
Step 9: Shout
We will use the laugh expression here since the jaw line is already properly drawn for an open mouth, which is needed for the shout expression.
For the mouth, don't touch the bottom lip, only the upper one by bowing the lip downwards, then adjust the bottom lip to the newly shaped upper one. What will really define this expression is the eyebrows and nose. While the bottom edge of the nose doesn't move, you want to push the nostrils upwards, as though they are flaring. As for the eyebrows, the inner corners can be pushed down in an exaggerated manner, going as far as touching the bridge of the nose and even drawing a line to connect one eyebrow to the other (without hairs). But keep the outer corners bowed upwards. To make the frown more prominent, draw to small lines between the eyebrows to show that the skin is pushing together there.
Step 10: Angry
For the angry expression we'll use the shout expression as base, since then we can leave the eyebrows and eyes as they are while only needing to work on the jawline and mouth. Since the mouth won't be open any longer, you want to move the jawline back up. As for the mouth, remove the teeth and tongue and then push the upper lip down and the bottom lip up. Make sure there is a small gap left to show a sliver of teeth, as though gritting the teeth together.
Step 11: Sad
Sad is easy after you've created the smile expression, since for the mouth, all you have to do is flip the center line of the mouth horizontally so that it bows down rather than up. The upper lip will need to be adjusted a bit, but nothing to complex! The eyebrows really help add to the expression. While the inner corners create a curve, the rest of the line follows the shape of the top line of the eye, pointing downwards.
Step 12: Crying
Using the sad expression, we'll keep the mouth as it is and work on the eyebrows and eyes.
While we want to keep the outer corners of the eyebrows where they are, we want to push the inner corners upwards. Like the sad eyebrows, create a small curve on the inner corners and then draw a straight line downwards. As for the eyes, remove the pupils and then push the bottom line upwards to make them seem more slitted and then redraw the pupils, pointing them somewhat downwards. People rarely look another person in the eye when they cry. To add to the expression, you can add two small lines between the eyebrows, to show the skin slightly pushes together there in sadness/worry. And then because it's the crying expression, add some tears!
Step 13: Worry
Here we'll use the sad expression as base since the eyebrows are in perfect place. You want to add worry lines of the forehead and to help define this expression further, by thinning out the bottom lip, it'll look as though she/he is bitting it in worry when allowing a little bit of teeth to show.
Tip: If you use the worry lines of the forehead with the eyebrows of disgust, the slitted eyes of angry and the mouth of kiss (will be shown in the next step), you get the expression: Pensive.
Step 14: Kiss
You can draw the kiss with open eyes, but it's not as effective. So, remove the top line and pupil, but keep the bottom line of the eyes. What you want to do, is thicken it a bit since you have the upper lashes and bottom lashes meshing together. You want to really curve the eyebrows, it'll give a relaxed feel to the face, but the feature that defines this expression is the mouth. You want to make the lips almost as wide as the nose, the center lip should bow up a little bit since generally people who want to kiss someone are happy, but, since the lips are pushed together, allow there to be wrinkly lines in the center. Two short and curved lines placed on top of one another (one facing up for the upper lip and the other facing down for the bottom lip). Drawing a heart can help to shape the lips around!
Once you've created the expression you wanted, you can continue onwards to make the hair and add the colors and shades! There are plenty of great tutorials on how to create vector portraits and vector hair right here on Vectortuts+!