Critique/help

I’ve been working on creating a whole fakemon dex for my Novum region. I find it fun and insightful to create some drawings of my fake pokemon living in the region. Kinda grounds them and helps me think of ways they will interact in the map.

What can I do to improve the art of these. They feel like odd and lower quality than some art I have scene and I want them to blend together a little better and have a higher quality render. Is it my shading, my line work, the colors. What should I be researching to improve my artwork.

Thanks!

These are made in procreate.