What you need to make a picture close to the images you show are:
- high quality textures
- high quality textures
- high quality textures (incl. cloudy skies)
Basically that's it.
Add a touch of eye for detail. Or two.

Then if you're ready with your design:
- make a few test renders,
- makie a few more test renders, changing the lighting, time of day and geograpic position and orientation.

Then, last of all, add a few trees that are NOT too heavy on the leaves. SH3D has trouble handling highly detailed trees with many thousands of leaves.

Hans
PS: your avatar makes me think of, well, uhm, emptiness.