The trees on your newest one are quite good, if you ask me. Probably better than what i could do, due to me not drawing trees very often. =P
The grass is also pretty good, with limited visible tiling. It does appear rather... Bland? But then again, the viewer isn't particularily close to the grass, so ehh.
The path, while doing a pretty good job to look dynamic, is just too undetailed. Perhaps you could add some roughness to it?
And finally, the tree trunks. They're probably the worst part of the image, sorry for putting it so bluntly. They're undetailed and not shaded well. Trees aren't all smooth, they have a very rough surface, as well as many branches. Mind you, not all trees have branches at the lower levels, but they're still covered in rough bark with plenty of flaws. For instance, instead of making the trunk like this:
You could make it like this:
Just remember to add loads of small details, even if it's just a totally random pattern for the bark. That's what i did, anyways.
In hindsight, i apologize if i've seemed rude at any point, as it wasn't my intention to be so.