Basic Form: Diamond

 Basic Form : Diamond Shape

 First, draw a shape(in 3D), then pic up to color in light, middle, and dark value. For me the color I choose is Teal, from a light color(you can pick white also) to dark color(not totally black), as shown below.

Color it up by choosing where the light come in contract with the object, and the shadow (dark part), then color it up. Add the light effect (light color) on the edge of the shape(diamond). For my design(as a student also), the light is from the second edge from left, White color is used as the light effect. then my diamond is done!