Need help with shading and lighting

[kind gale]

I just don’t know how to improve it

[simple tartan]

I think this already looks really really good - only thing I would say is to choose a direction that the lighting is coming from (it looks like maybe from the top here or from the front) and then remember when shading to always follow that direction for shadows and lighting- another thing I would say is don’t be scared to add darker values for shadows because the darker you go for the shadows, the more contrast it will add against the lighter areas. I love this though, and your arty style is so cool. :)