Start with a simple curved line to set the direction of the curl
Add a second line parallel to the first to define the thickness
Tighten the curve gradually toward the end
Overlap the lines slightly to show the curl folding inward
Vary the line width to suggest depth
Add a small spiral or loop at the tip if needed
Shade the inner side of the curl darker
Keep the outer edge lighter and smoother
Refine the shape until the curl looks natural