Drawing eyebrows

Usually, after someone have drawn the eye, you usually just jump right into drawing the eyebrow. The eyebrows are arc shaped lines of hair, basically. They are very complicated, yet overlooked. If you were to draw an eye correctly, and you draw the eyebrow incorrectly it could throw off everything.
There are different ways of drawing the eyebrow. These different ways are used to show different expressions. For example, if the eyebrow is closer to the eye, and it is curving upward, with stress lines/wrinkles underneath, then that character is most likely mad or angry.
If the eyebrow is at a regular ark, then the person is usually happy.