Newbie looking for guidance

[Zheios]

Hello everyone! I'm pretty new to pixel art and I have stumbled upon this forum yesterday while looking at other people's work to try and grasp the basics of drawing with pixels. This morning I decided to give it a go and made my first piece, which is this tree ! I discovered that making a tree's leaves texture is not that easy so I kinda went with how I felt and re-adjusted while working on it. I think what it lacks the most are some highlights and maybe a more precise sense of light source. I'm quite content with how the trunk turned out, but I think it looks like it is being seen from the front and not the standard view we often see in RPGs. Anyway, sorry for the long text; any guidance or C+C would be most welcomed. Thank you and have a nice day. 
 

(I hope the image comes out right, I just uploaded it on imgur with its original size)

[Decroded]

Welcome, good start 

Perspective of leaf structure vs roots suggests eye level perspective, is that what you're going for?

Consistent light across the textures flattens the image.
Consider shifting the light source a little to the left or right so you can use light and shade to out the forms.

Try adding more yellow hue where the sun hits the leaves.

EDIT: Made a quick edit for you to illustrate:

[Zheios]

First, thank you for your reply ! On the matter of perspective, I haven't really thought about that. I just tried to make the textures look like what they were supposed to be. I will try to shift the light source like you suggested, it really seems to make the image more "real". I tried to stay away from hue shifting as I kinda suck with color and can't seem to grasp how to make good contrast and colors connect.

I will follow your guidance and post the result once I find the time to work on it, again thanks a lot for your advice !

EDIT: I worked on it a little bit and this is the result. I think it is a lot better, thank you !