Draw a vertical line. Make a mark in the middle to position the eyes.
Make 4 more marks around this point.
Connect the points you made to create the shape of the face.
Start by drawing the eyes. Make sure they are both looking in the same direction.
The shape of the eyes and eyebrows can drastically change depending on the character you are drawing.
A simple curve is enough for the nose.
The mouth is positioned between the chin and the nose.
The ears will be placed between the nose and the eyebrows.
The hair should start from the top of the head and extend downward. There's no need to draw too much detail.
When drawing the eyes, make sure you can clearly distinguish the pupils from the rest.
Darken some lines to increase contrast, and finish the lips.
As you can see from this drawing, the eyes and the mouth are the predominant features of manga characters.