Those small rocks under the water are ugly, make bigger ones instead, always looked nicer that way.
The green grass near the water doesn't fit in my option, tint it down.
The water is empty, add some life (fishes, grass).
If it isn't a playable terrain you can always add clouds, but tint them down to 15/15/15 and then spam them.
Those same trees are boring, try using different ones.
The cave is pretty much empty there, could use some stalagmites and vines.
On the right side of the picture that big cliff looks like it's hanging, which looks awfully unrealistic, put some rocks underneath (Not small ones, but bigger)
That grass on the ground doesn't fit well with the trees, you should either tint down the grass to yellow/brown to fit the trees or change the trees with some green leafs.
The grass is also boring, add more types of grass, flowers, ferns and etc.
Some larger rocks on the ground could be good, because it will look as if they felt down to the ground from the cliff.
The cliffs could also use some greenish stuff, like grass or some branches.
Add light around the camp fire.
And you can always add some ruins, they will always look good.
You can do much better then this, I know it!