In this case, I used other adjustments like Levels, Hue/Saturation, Brightness/Contrast and finally Curves to improve the lower part of the picture. You can apply as many adjustments you like until you are happy how that particular section of your picture looks. But as in Step 3, we now have the problem that the sky looks to fake (well, even more than before). Next steps will show how we can fix that. Yes! Your are right. Of course we are going to fix it with our History Brush Tool.