Draw a small spiral or oval shape for the shell’s center
Add curved lines spiraling outward from the center
Extend the shell shape into a wider fan or teardrop form
Draw ridges from the center to the outer edge
Add a slightly wavy outer outline
Refine the curves to make the shell look layered
Erase extra sketch lines
Outline the final shape clearly
Shade along the ridges and inner curves
Add highlights to show texture and depth