What is actually done when sharpening and cuping a model propeller?

Which faces of the raw propeller blades do you grind off and which ones do you leave alone when sharpening. Leading edge only or both leading and trailing edge of the blade sharpened? To a fine thin edge or to a clever shape

What exactly do you grind/bend? to "cup" a propeller?

Do you only sharpen the propeller edges or do you grind the whole blade to make it thinner as well? If so how thin?

Do you try for an aerofoil blade shape like a planes wing or unifom thickness across the blade?

What tools work best? Dremmel tool? Air grinder? What dremmel/grinder bits to use for what operation? All by filing? Wet dry sand paper? Stone?

How and with what do you polish the prop when done shaping?

Etc? Etc?