First light and shadow practice, any advice?

[marsh vessel]

I got inspired and mostly based myself off th ref image + I'm pretty happy of it considering its my first try, any critique would be nice

[tight meadow]

I believe there isn’t enough values, currently there’s only 3 different values, light gray, dark gray and black. While in the photo there’s around 7 if you simplify it. You are also missing some shading on the cheek and the shadow over the left eye looks too flat, it should be at a higher angle. You are also forgetting the reflective light coming from down up and the light bouncing off the hair

Or, if you want you can try to lean more towards a clip art feel by simplifying and blocking up the shadows instead of blending them as much