Facial expressions are universal, they are the expression of emotion. They are not taught different in other cultures around the world. If you are happy, you smile. If you're sad, you smile. Surprised is the same facial expression everywhere. If you were in a different country and you saw someone frown, you would know that the are unhappy.
*Remember in both projects to put big triangles where not a lot of detail is required (Shirt, hair, neck, skin) and to put smaller triangles where detail is needed (eyes, nose, mouth)*
-If you don't like how poly-1 looked, you can create poly-2. You start by first taking your image and placing it into Photoshop, then you can lock the background layer and "command J" it to copy the layer. Once you have the second layer, name it "Low Poly". Then you can start working. You go to the polygonal lasso tool (press "L" to use it) and creating a triangle. It is better if you start in the chest area. After that, you do the hair then do the neck, then the skin, then the main features like the eyes and mouth. Once you have the triangle, you can click "I" for the eyedropper tool, then you can find the color that you want that triangle to be, every triangle should be a different color. Once you get the color, press "alt" and "delete" at the same time to apply the color. Do that until the image is finished.