/ic/ - Artwork/Critique

Need some advice
When i do shadows and light digitally, I've tried two methods. Hard round, and soft round brush.
When I use hard round, I get cell shading style. When I get soft round, I get a gross airbrush looking thing as in pic related.
I want to have more control over my brush work, and I can only really do that with cell shading. Is there a specific technique or brush or brush setting to use? Pic related was Soft round with pressure opacity.
I know my knowledge of light is still lacking and needs to be slowly improved but I'm really sick of either going "Oh, I guess Im gonna do this with cell shading again or try with an airbrush and maybe make it look shit"
I understand as your knowledge of form increases, so does your knowledge of where light and shadow accumalate. But I just feel like I don't understand photoshop. I watched this video https://www.youtube.com/watch?v=vZ5ulFxA-eA& and I loved how his stuff turned out, but I feel like all im missing is the brushes he made.
I could be wrong. I am new. Give me some advice please