Luminosity masks
Luminosity masks are selections based on your image's brightness: the lighter a pixel, the stronger it sits in the mask. That lets you apply adjustments very precisely to only the highlights, midtones or shadows. It is a beloved technique among landscape photographers.
Make a luminosity selection by Ctrl-clicking the RGB channel and refine it with extra channel operations, or use a dedicated plug-in. Turn the selection into a mask on an adjustment layer, so you can darken only the sky, for example, without touching the foreground. The transitions are soft and self-feathering, so edges stay natural. Tip: combine a highlights mask with a gentle curve to subtly recover blown-out skies.
Related terms
Prefer a look in one click?
The presets on this site set these adjustments up for you as a starting point, which you then fine-tune to taste.