The images are easy to find online. I searched Pre-Columbian sculpture and Greek sculpture. Something tells me these are not the only nudes on the web.
You can try painting the shadow shape alone, to see how much of the presence of the whole figure it carries. Or try being careful with the shadows and carefree with the first layer lights. You can play with hard and soft edges on the shadow shapes. Color temperature contrast. Counterpoint between figure and ground (light behind the dark, dark behind the light). Have fun.