Draw curved, flowing lines to suggest movement
Use long, sweeping strokes that trail across the page
Add repeated wisps or streaks in one direction
Vary line thickness to show stronger and weaker gusts
Make some lines taper at the ends
Include swirls or spirals for swirling wind
Draw leaves, grass, or dust being pushed by the wind
Tilt nearby objects to show wind direction
Leave open space so the wind feels invisible
Keep the lines light and airy