Observe the big basic shapes, such as circles, squares and triangles, that are evident in the structure of the subject.
Start by drawing the biggest, most obvious basic shapes.
Progressively add smaller shapes to fill in the subject.
The simplest way to improve your drawing skills is to do it. Sketching on a regular basis, just 5–10 minutes at a time, will help you develop your drawing skills through active observation.
Add the details to the basic structural shapes and develop the overall form of your subject.