In reality (industry/jobsite), you learn courses 101-303 at-the-same-time.
When you press (alt/opt. + click the 'create a new layer' button) you get the "New Layer" box.
There are more ways to get to this 'box'. Ask google.
Copy what I clicked.
My ex-NY photographer friend Taichi showed me this trick.
I created this 'Soft Light-neutral' layer to trick the computer.
This is how it works.
Layer (Neutral + Contrast = Nothing happens) + (burn'-n'-dodge tool) = Super-safe light-data quick Burn-n-Dodge layer that does not affect the pixel. It's an overcast.
(**There are advantages and dis-advantages using any tricks. Please b smart)
Burn and Dodge tool affects pixel itself. This trick is to avoid direct interaction between the two. This trick is standard in some part of the industry.
The advantage of Burn and Dodge tool is standard in retouching skins.
It's the most delicate tool that has the versatility and ideal effect over pixels when recreating beautiful skin.
right image is brightened
compare and contrast
this is about 60-80% done
Usually, you would zoom to 400% and be using a wacom pen, at brush-size aligned to skin's each creases with strength 2-5% for burning, 5-10% for dodging ("It always burns faster").
That is for high-standard fashion and it takes x8-time to complete.
For I-Don't-need-to-Cyborg photos, I only zoom to 200%, and would be using watevs that makes him look good.