Focus on the Basic Structure
A structural sketch will help you observe and understand the underlying structure of the subject. Here you will focus on the placement and proportions of the elements rather than on light or shadows.
A structural sketch is the basic linework in which values and details are built upon. They are a great way to observe your subject, and are often used as a basis for a more finished drawing. A structural sketch is also an excellent way to loosen up before doing another type of sketch or drawing.
Focus on the Basic Structure
A structural sketch will help you observe and understand the underlying structure of the subject. Here you will focus on the placement and proportions of the elements rather than on light or shadows.