To make the process simpler, begin by identifying the major shapes. These are the shapes that need to be separated from each other in order to understand where they are in the illusory space. In the image above, the building on the right is farther away from us than the school bus, but closer than the dark green hill. To get the building to separate from its neighboring shapes it must be different from them in terms of value and/or color (for this exercise let's treat all edges between shapes as hard edges. Two variables are enough.)
For each of the major shapes, choose a color and value that will separate it from the adjacent shapes. Try to ignore the texture. The job is to deliberately oversimplify the information. The windows on the building, for example, could be left out without undermining the feeling of space. Put them in if you want, but first establish what you see when you squint.
How about the bus? Think light, middle, dark. The whole shape can be painted the sunlit local color, except the windshield. Then, when that's dry the right side gets a second layer of middle value. Then a few dark windows and stripes, if necessary.
Remember, this is a study. We want to find out if the illusion of light and space can be established with a minimal treatment. That will reveal what really needs to be in the painting. When the shapes have all been blocked in, ask where you would want greater subtlety or specificity. Make notes, but don't embellish the study tool much. Leave it too simple. The best way to find out if something belongs in the painting is to leave it out. If you have time, use the study as a road map for a proper painting.
How many shapes does the pile of logs represent? The key word is "pile".