Scott demonstrates placement using a limited number of lines in a scene where the sky plane is dominant.
Begin by identifying the major shapes in the scene -- limit yourself to shapes that can be described with "ten lines".
There is no magic to the number 10 -- describe the major shapes in as few lines as possible.
Often you will use "ten lines" to decide the amount and shape of the major planes (sky, vertical, slanted and ground).
Experiment with different placement, size and form for the major shapes.
The idea isn't to render the scene exactly as you see it. The scene will change based on your location within the landscape (where you are standing, etc.) and/or the time of day. Imagine these changes and experiment with their impact.
Use "ten lines" to divide your surface into interesting spaces.
Placement first. Refining lines and drawing second.