Good morning, Tropical Bird, and welcome aboard to line of action, I'm Polyvios Animations. How are you doing?
Nice job on your range of line weights on all of your faces, expressions, and figure studies, even your quick sketches of hands, because of the range of expression and emotion of the lines and the storytelling and acting possibilities. Please kindly keep them going! But, I totally also love how really great a job on analyzing your anatomy of the bone structure of your hands. Please do keep on pushing yourself as far as you can go.
Go as far as you can go, and then go farther; Know what you're gonna draw is actually gonna work the first time.
However, these lines in their looseness of all these subjects and fan arts are totally and completely not loose enough to me yet. Why don't you please free up your range of storytelling drawings of those thingies with 5x5 minutes of figures, 5x5 minutes of faces and expressions, and a 10 minute warm up of a hand? ((5x5)+(5x5)+10) (50+10)=1 hour of drawing practice.
The reason why you could and should, and would go ahead with this deliberate practice is because your storytelling poses and expressions, and gestures will become less mechanical and much, much, MUCH dynamic, fluid, flowing and organic in your graphic narrative uses.
Don't be really half-hearted, learn a new move by exaggerating it.
The Little Book of Talent, Daniel Coyle.
(Confidentially, it was just a paraphrasing.) For more info, please look into a book or Audible of the book with the same name. Hope these have helped you out so much.