“…develop the habit of painting all your ‘darks’ with less pigment than you would use in the ‘lights’
“… paint your darks thinly, almost stain-like, to begin with; they will recede better. Most darks occur under forms.”
John F Carlson, “Carlson’s Guide to Landscape Painting”, page 27
[For “pigment”, think “thickness of paint”.]
The Old Masters often have the lightest lights as the very top layer of paint.
Take a look at Rembrandt, for instance, and his top-level lights on those ear-tickling lacy collars so many people are wearing in his portraits. Look at his paint handling in his darks, and how his lights got thicker and crustier in his later paintings. The London National Gallery’s website lets you zoom in on photos e.g. Self Portrait at 63.
Painting from dark to light.