This task is the most difficult one for me because this is my first time using illustrator. As a beginner, making shadow from the base model need a precise and accurate shape based on where the lights (highlight tones) come from, So the picture above shows that I can only manage to do the Circle shadow cause it is simple to do. Other than that, I can only do the highlight gradient with white/black and vector colors. First Row is BASE MODEL, Second Row is GRADIENT SHADING and the Third Row is VECTOR SHADING.