The best way to remove a crayon stain is with W2-40 (also effective at removing crayon from walls). Spray WD-40 on both sides of the crayon stain. Let the solution sit for 3-5 minutes before rinsing thoroughly.
Rub dishwashing liquid into the stained area with a clean cloth, changing sections of the cloth as the crayon stain begins to bleed away. Repeat until the crayon is removed.
Apply a stain remover stick, gel, or spray to the crayon stain. Let sit for 3-5 minutes.
Wash in the hottest water that the fabric can safely tolerate.