Draw a small circle or cloud shape at the top
Sketch a wide, curved funnel extending downward
Narrow the funnel as it goes lower
Add a swirling, spiral motion inside the funnel
Draw a wider base near the bottom if desired
Add curved wind lines around the tornado
Sketch small debris shapes around the funnel
Darken the outline of the tornado
Shade the funnel with varying tones
Erase extra sketch lines and clean up the drawing