This is a basic exploration in line. Use repetition, symmetry, asymmetry, line-width, and even value to illustrate content. Your subject matter does not have to be sensical or logical. Here I used vertebrae, leaves, and botanical forms. There are also some pearls, moons, stars, and scale-like shapes in there too.
Next, apply color using tissue paper, watercolor, ink, gouache, or other pigment.