One thing I'm trying with this sketch is working from a b&w reference photo. I'm hoping it will help get the tones relatively correct with more ease and not being fooled by changes in colour.
I did a crosshatch with the watercolour pencils to add colour to the background. Then I tried to take that texture out with a wet paintbrush and just have a solid colour background. I didn't bother to scrub all lines out. I figure when I add the grass in with the pencils after the paper dries, it won't be too noticeable
After the paper dried I added more lines for hair and grass and emphasized the dark part of the eyes, nose, and mouth.
I'm pretty happy with the end result. There wasn't as much magic if paint is applied on wet paper with a brush. But I'll stick with this technique for a few more paintings and see if it keeps improving.