There are two parts to drawing. One is the technical execution of drawing itself – a pure mechanical skill. This is the hand-eye-brain coordination which can be trained and perfected over time. For example, by drawing something everyday in a sketchbook for 1 year straight, you will definitely draw better at the end of the 365 days. Therefore, it’s no wonder young students who drew “all their life” tends to accelerate quickly and learn much faster in school. They’ve had 10+ years of training their eyes, hands and brain to work together as one.
The second part has to do with understanding and building of the visual libraries in your brain. A designer’s job is to solve problems. But to solve a problem, you first have to understand the subject matter. By analyzing what you are drawing, you fill your brain with potential solutions and visual ideas. Some of these elements include the understanding of forms, perspective, materials, lighting, and composition. On the visual library side, by sketching subjects such as birds, plants, airplanes, cars, insects, people, etc. you slowly introduce your brain to the shapes and proportions which make up these subjects.via fzdschool.com