shading practice with my on-screen tablet

I recently started drawing on my tablet because I figured getting into digital art is pretty useful, and I want to encourage myself to try to fully colour-render things instead of just leaving my sketches as is. So this sketch is just my first attempt at basic shading placement and stuff, I didn't follow a tutorial and just kinda.. guessed.

I started with a midtone, then deep shadows, then lighter areas where I softened up some edges.

Right now I kinda wonder what to do with the midtones and if I should expand the shade range there, and what to do with factors like blush, reflected light, half-shadows and the like. But that's what the tutorials are for.

If you are reading this and you may habe some critique, suggestions, advice, I'd love to hear C: