how to improve an art in light and shadow?

[kind spire]

Hello, I'd like to ask how to improve this art in light and shadow. And I know that line is also poor so if you have more time, will you explain how to draw line more clearly?

[timid trout]

i think you need more contrast in your values, it's very dark right now

try to follow a 70/30 (or basically just one a good bit more than the other) split of light and dark

also, don't be afraid to use more hard shadows. especially on the face and body you used a lot of airbrushing

[unborn ore]

heyo this is just my opinion, but i think ur colours r perfect. i think instead try adjusting how u render, it can help a ton w clarity + form. to show light properly, focus on adding big blocks of light/shadow rather than adding lines of light. ive made a quick repaint to demonstrate :D

[kind spire]

Thank you!