Hue adjusts the actual colors of the image. We can adjust how individual colors behave. This is extremely useful in landscape work, where you can fine-tune the
color of greens and blues, for instance, without affecting browns or
oranges. This is great for altering foliage and sky, without adjusting
sticks, dirt, etc. It also works well if you have a human subject in
your landscape: you end up with nice bright foliage and a nice deep blue
sky, but your subject can still have nice, normal, subtle and subdued skin tones.
Saturation slider is a huge help when you want to boost a certain colour
over another: I often boost blues and greens on landscapes and
sometimes bring yellows, oranges, or reds down in portraits to ease skin
tones.
Luminosity is something a drastic. It's minor, but
it's there, and it's one of those little touches that will really seal
the deal.
The big thing with the HSL Sliders is to try them and experiment: In
many cases, you never know what will look good or not unless you just go
ahead and try, and dont be afraid to get drastic.
