Value is the support of a painting and guides a viewer.
Artists use a painting value scale that runs between a darkest dark, black, and lightest light, white.
Before you begin a painting, determine where that darkest darks and lightest lights are located and write it down.
So – what do you want people to look at? Once you decide, do a quick value study (thumbnail) showing just your darks, lights, and mid values. It simplifies things to do your drawing on a mid toned background which is used as your mid tone.
Because the human eye sees contrast first, people will look where that contrast is the highest. This makes a focal point.
Mix your darkest dark colour (it may not be as dark as black) and your lightest light.
All other colours in your painting should be subservient to these two, having no other areas of that much contrast elsewhere in the painting.
This is a 3” square thumbnail using a pencil and black and white conte crayons on toned paper.
I wanted to highlight the brilliant snow cap on top of the right cliff, making all other areas of contrast less intense.
Here is the final painting. If you squint, you see that all other areas have less contrast that that focal point. You can also edit a photo of your painting to black and white to check values (as below).