My friend J. send me another image and asked me for opinion. With her
permission I am including my answer here, with hope it can be useful to
some more. Later I may extend this article by adding some tips and
examples.
Looking at your image apart from fixing dark part (look at attached
image), there is not much from technical point of view to make better.
Nice is how tree and stones in foreground frame the hills on horizon.
However there is one fundamental problem with this image. That problem is
very common and it is one of the most difficult to fix.
It is about how our brain works when looking and the scene. Our brain
filter automatically unimportant things from the scene and place emphasis
on the items in scene which we find important.
Photo camera is not able to do it. So when we take picture of something we
find interesting, later by looking at the print we realize that there are
too many things and a lot of them is disturbing. We find out that the one
or few items important to us are lost in the image. Other people looking at
the same image do not know why we took image. They do not know what we saw
important on that image.
So art of making good image is to filter out at the time of exposure what
is important and what is not by making the right composition.
We can make it partially later by darkening and lightening of part of
image to put focus on important thing.
On your image however I have no idea what was the important thing why you
took this image. There is too many things. Stones on left part of the
image, hills at the horizon.
So I can not use darkening and lightening technique to make change which
would put focus on one or very few items with the most important in image.
Some images do not have focus point, but in that case they contain
extremely few objects and actually creates more poetical feeling that
documentation value.