So I tried and uh, you got some great art I am not sure what you need to improve on ^^"""" but that could be due to my own inexperience in art as well.
I'll list some things here, but keep in mind I am not the greatest artist on site.
Art traits: (these are not critiques, what is a con for one artstlye is point of another, so draw how you want to-I guess you just want to experiment?)
-nonexistent-thin black lines, there is certain messiness/energy and sketchiness to all of them in varying degrees, but lines are no what some would refer to as clean-cut
-blended shading/lighting in small doses for most art pieces thou it might be cause compositions do not need more dramatic shadow/light display so lines are ones carrying/giving us idea of form and flow
-simple textures once again defined/differentiated mostly due to linework
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Eh, honestly I think you might benefit the most from doing one of those multiple styles challenges like on TikTok , where people try like realism, anime, manga, american comic, pop art, cartoon network style, disney, cubism. Or if you did not do so yet try to learn through YouTube videos or real life books things like color theory, composition, perpective? I don't know much about these either yet so I cannot say if you use them well or not, but I think it is going well cause I did not really pick up on anything odd looking for seemingly no reason.