As soon as possible, rinse the stained spot with cold water. Apply a tiny amount of liquid detergent or soap. Rub the spot gently and let it sit for several minutes. Rinse again with cold water. Repeat if needed.
Rinse the item of clothing with cold water and blot with a towel. Apply a small amount of a mild detergent to the stain and rub with your fingers. Then rinse again. Launder as soon as possible and leave to air dry.