Basic exercise d It is convenient to do it with soft pencils; 2B onwards, the ideal is 4B in the first sections, followed by 6B in the middle parts, and 8B and even 9B in the area where it is closer to black.
This type of work will help us to discern a wide tonal range when we are doing more sophisticated work.
But the most interesting part of the graphic or diagram is the part of the Gradient.
There will be no limitation of borders in this long monolith or rectangle; of the two that will have been previously drawn following a minimum method with the composition rule on the page... respecting the horizontal and above all the vertical halves. This will help us, in the future, for example, for skies, which will be chromatic but at the end of the day the base is the same.