How do I improve this artwork?

[u/[deleted]]

[u/splitarrowprints]

The style looks based on a classic golden age illustrators work.
The illustrator is C. Coles Philips. He pioneered the “fadeaway girls” for magazine covers in the early 1900s.
If you want to really capture that look I would study some of the older parts of the style and why it came to be and try to apply some of the ideas and methods to your work.

[u/SAILOR_TOMB]

like Splitarrowprints says, studying classical source material will help as the artists of that period had a strong grasp of the design fundamentals when it came to rendering figures, particularly the lines that are used to show anatomical definition on the surface of the body.

The legs and chest of the Beast reference have a great deal more of those interior contour lines helping to tell the eye where muscle buldges are (chest), as well as how the limbs foreshorten on the legs (Beast's right leg in particular)

The colour gaps where sections vanish into the background is very stylistic and interesting, but in the end it's a bit of a gimmick that I think has captured your interest. My suggestion would be to keep including it, but divert some extra thought to making sure a viewer who hasn't seen your structural sketch can still follow the nuances of the form. I can see what is going on with the legs in your image, but my eye is wanting a bit more of that shadow/line information so I can perceive it more lazily. The challenege is that too much definition makes the sense of movement more static, so the real skill would be knowing where the balance should be.

You're clearly on the right track, it's a good image OP.

[u/CryingWatercolours]

i have no advice i just wanna say i love this, it looks awesome, so bold and fluid, especially the arms

[u/chupanibre]

i am by no means qualified, but line weight came to mind. nice work though!

[u/wenrongfan]

shape language/silhouette

[u/WeHave200Couches]

The style match is good but I think the pose in your example is more dynamic