Faces help tell the story, so learning to draw them correctly in manga is very important. It will help you draw better if you familiarize yourself with where the features sit on the face in relationship to each other. Female faces are usually a little smaller and rounder, while male faces are a little longer and more angular. Eyes on males may be smaller.
To begin your drawing, lightly sketch out a circle. Divide the circle into thirds horizontally, and then draw a vertical line down the center. Make sure these lines are light enough to erase later. These will be your guide lines. Don't worry if your circle is not divided perfectly... no face is perfect anyway.
Next, extend your vertical line beneath the circle about the same length that it runs through the lowest third of your circle. Make a little horizontal mark at the end of it. This will be the bottom of the chin. Depending on the face you want to draw, this mark will be higher or lower depending on the ultimate face shape you wish to draw. Next, draw two more light lines from the bottom edge of the circle towards your chin mark, one on each side of the circle. Use these lines as guides to flesh out the cheeks.
In general, the eyes will be placed in the lower third of the circle. Eyes are begun with simple circles. Lines can be applied on the top and bottom to form eyelids. Depending on how these lines are drawn, your character will alter their expression. The eyelid lines will be heavier than the rest you've drawn to this point. Add a light reflection at the top of the iris, off to one side. Make sure the reflections in both eyes are similar, since they reflect the direction of the light source. Sometimes smaller ones appear on the other side of the iris. The pupil is another circle in the center of the iris, only it will be dark and placed behind the reflections. Darken the iris a bit where it meets the upper eyelid, and again on the opposite side of the iris on the bottom. The area between the pupil and the edge of the iris will be eye color (leave reflections white).
The mouth is about halfway between the eyes and the chin. Place the nose between the mouth and eyes. Erase your face guidelines and add some hair. Hair can be tricky. Draw your hair in fast, short strokes, making the outline of where you want the hair to be. When you are happy with the result, don't forget to add some white space for highlights. Add a little shading to add depth to the hair in the back and around the neck. When you add the neck, remember that females have thinner necks in general, and males have necks that are a little thicker.
The great thing about manga is you can convey many different emotions by using minimal lines. Twist the mouth up a little for a smirk. Add a curved line below a small straight line to create a big smile. The important thing is to practice a lot and have fun.
Next: Drawing Expressions