Use a dry microfiber cloth to wipe the wall
Rub the crayon mark with a clean white eraser
Apply a small amount of baking soda mixed with water and gently scrub with a soft cloth
Use a damp cloth with a little dish soap and wipe the area
Try a magic eraser lightly on the crayon stain
Use a hair dryer to warm the crayon, then wipe it off with a cloth
Apply a small amount of white toothpaste and rub gently, then wipe clean
Use rubbing alcohol on a cloth for stubborn marks
Test any cleaner on a hidden spot first
Dry the wall with a clean cloth after cleaning