Gently scrape off excess crayon with a plastic scraper or old credit card
Rub the mark with a clean dry microfiber cloth
Apply a small amount of baking soda mixed with water and wipe gently
Use a damp cloth with a little dish soap and wipe the area
Try a melamine foam sponge lightly on the stain
Wipe with a cloth dampened with white vinegar
Use a small amount of non-gel toothpaste and rub gently
Clean the wall with plain water afterward
Dry the wall with a clean towel
Test any cleaner on a hidden spot first