Hey there, off to a good start. But there are a few ways to improve your soldier:
It looks like your making a top-down sprite, so I changed the perspective a bit and then added some extra shades.
You can use shading to make your sprite feel less flat and more three-dimensional.
Then I added and removed some additional details to make the sprite more readible.
I prefer to not use to many black lines within a sprite to allow for more details.
I googled some forest soldiers and foud some more brownish greens, so i tried some of those in the last version.
Hope this helps.
