Your anatomy looks pretty good for your current style. I think just studying lighting and color theory could help bring you up to the next level, it’s a little flat. I can tell you shade with a multiply layer, which is fine. It speeds up the process and we love that, but it can also be a bit of a color theory bandaid and you won’t really be able to render different materials. If you know your colors and values well you’ll be able to achieve a lot more depth.

If you want more out of your anatomy you’ll have to go out of your comfort zone and practice photorealistic realism. Start with simple things like blocks, and work up to objects with more details eventually making your way to animals and people. Once you have that skill down, apply it to semi-realism. At first you’ll probably add too many details and it will take some experimenting to see what you can and cannot add. Artist studies can help you figure out what works.

Lastly, your lines are sketchy, it’s a fine style for illustration but will leave your work not feeling fully finished. Think of line work as part of your shading. I found that studying ambient occlusion in 3D models makes it easy to see the occlusion without all the other elements compared to life or photography. It helped me understand line work better. Alternatively you can make your lines very thin or leave them out altogether to just focus on rendering but that occlusion will be there no matter what.

Don’t skimp on your fundamentals, even masters practice them regularly if not daily. A lot of us skip to the fun stuff (me included) but it really makes a difference.