What is the suitable contouring method for a square face?

I first learned the meaning of contouring through Unpa. It is described as a makeup technique that enhances facial contours to make the face look three-dimensional. It is a technique commonly used on the forehead, nose bridge, and cheekbones, but the term itself is unfamiliar to me.

I have a distinct square jaw, so I shade to slim my jawline. However, the boundaries are sometimes indistinct, which can make my face look even more angular. What is a natural contouring method for the space between my prominent cheekbones and my square jaw? I am really envious of those who see such dramatic results before and after makeup. This is the shading product I usually use; it is a versatile tool that works as eyeshadow, blush, and more.