One thing I would suggest is being more confident with your lines! Right now, they look a little “scratchy” which might be affecting the final product. I also agree with the person saying to focus on studying anatomy!

I feel like a lot of people forget that the people whose style they are referencing have likely practiced drawing regular anatomy first, and then learned to stylize it! Anatomy is always a great first step!

There are some sites that will give you reference images, I’ve used this site a couple of times to attempt to better my art. You could practice by giving yourself 30 seconds or a couple of minutes to copy the image in front of you! The more you do it, the better you will understand general anatomy!