Another attempt at P1 Observing Shadow and Light formations on a surface

I've had another go at this but am REALLY finding tone hard to do. I feel 'line' are now coming along but 'tone' still needs a lot of work. I can see the different tones by following the screw your eyes up mrthod but I just can't translate what I can see visually into what I am drawing. This is just an area where I have to keep trying and trying more.