bbreakfast:
i tried to go pixelation-style edit mode on the tree (it's hard to explain some concepts without actually trying it myself)
basically i think you've got some pillow shading going on. It's still good, but it has the pillow-shadiness where the darkest shade acts as outline about everywhere inside the objects and the brightest shade also shows up about everywhere on the object.
the light values still trend towards the lit side, and the dark values trend towards the unlit sides, but I wanted more of that.
the first thing I tried was the dead tree without leaves. in a nutshell, i just removed all the highlights from the shadowed areas. I then removed all the dark outlines in the middle of the lit parts. I actually recommend this a lot! Because pixels are so large in comparison to what you're trying to paint with them, a big black line in the middle of highlights reads as a very deep shadow.
this turns contraproductive when we're trying to convey the large cylinder shape of the tree, thus the dark lines mostly show up in the areas that bridge the lit and shadowed areas.
also not the thick area of pure dark pixels to the right of the tree. this is also to convey the larger cylindrical nature of the trunk. when there's shadow and light evenly distributed across the trunk, the eye will read it as flat, especially with so much detail inside.
i also put more pixels into the highlights!
onwards; i also tried to redraw the foliage of the beleaved tree. Again, i find that the tree is shaded in a way reminiscent of cotton. I tried to think about how to convey the double nature of leaves; their clusters form round shapes that reflect light as such, but leaves also have sharp edges and i find that one of the significant traits of foliage is the sharp contrast between ligth and shadow.
these are kind of at odds with each other, and as i don't intend to entirely redraw the tree, i ended up with something messy, that still somewhat conveys what i had on my mind. Anyhow, i think it's important with leaves to not always bridge between the lightest and darkest shade with a full ramp: i think it makes the leaves look too smooth and cotton:y. having areas of large contrast is important. I mean, disregard all this is you enjoy the cotton-like miniature feel of what you've already got: it looks very good regardless C:
please ask if you have any questions! also I know that some people don't appreciate paint-over edits, so please just tell me what you think. Cheers.