So I thought I'd put up a step-by-step visual of a character portrait. This is just a quick one I whipped up so sorry for the lack of quality (I'll post up a quality portrait some time in the future). In this you can see how I use lines and shapes to create a frame for a characters face and how I use the frame to create a face over top of it. If you have any questions I'd love to answer them. This is as per MS Paint.