Hello! I love your creativity and approach to this exercise--they're wonderful designs. I jotted down some feedback for one of the images that I hope is useful across the board. Overall, I would recommend to continuously zoom out, assess the big picture and think about how the individual elements in the image would affect each other. Right now it seems like you're taking a single element at a time to render, which makes things feel disjointed. Keep an eye out on your use of edges and values to group areas of your picture. This is where studying your favorite masters helps a great deal, take some time to look at how they approach this. Also, I agree with Rebecca on studying color, and I think plein air painting would be good practice to address all of the aforementioned concerns--and it's a lot of fun :) Hope this helps. Keep up the great work!

I love your layout design and composition in every single one of them. I would say your weakness is color, especially green. All your green looks very mottled with over saturated greens and unnaturally muddy greens combined. I notice for most digital artists green is a problem. Try to do life sketches of plants and trees with digital media. The yellow of the leopard is mottled too. Color harmony is not there either, except your 3rd and 4th piece. I recommend Marco Buccio’s color course here for color theory. His content is excellent and he explains everything so well! Also do some master copies of editorial illustration with a focus on how colors are used.