Lighting Study 1

I recently joined an art group and after they gave me some feedback on some of my art, I was told that I needed to broaden my understanding of lighting. Lighting is certainly something I struggle to understand immensely, and they pointed me to something I could read up on to understand this further. So I've indulged in simply trying to understand more of it through these shapes, though I couldn't help being curious and applying the concepts onto a human bust at the end. 😅

I was also striving to render more comfortably in this lineless art style again, but make further strides towards a style similar to that of concept art in Guild Wars 2. I realized I could attempt to do this by softening the edges of the darker areas with a soft round brush. You can see this effect at the bottom row of the image.