One of the most important digital darkroom skills is analyzing an image when you open it.
If you ask yourself what you don't like about an image - what's wrong with it - you can easily figure out how to improve it.
Here was my analysis of the top picture - taken in Mongolia in extremely dusty and overcast conditions:
Problem: No deep shadows and no highlights
Solution: Adjust Levels
Solution: Boost Contrast
Problem: Could not see faces
Solution: Adjust Shadows/Highlights
The next time you open an image, take some time to analyze it. The more you analyze, the better you become at self analysis.
Explore the Light,