Eyebrows has as much character as any part of the face. In anime, though, the eyebrows tend to be drawn generically making all character's basically have the same kind. Above left are several samples of eyebrows. At the bottom are two examples of the most common drawing of eyebrows in anime. The three initial examples shows how differences in thickness and even the shape of the eyebrow has a different effect overall.
When drawing eyebrows on quarter and side views, the shape of the eyebrow must also be reflected in your drawing. Eyebrows at these two points of views are similar all the time so just keep it in mind you're drawing.