Rinse the stain with cold water as soon as possible
Pre-treat with liquid laundry detergent or dish soap
Rub a paste of baking soda and water into the stain
Soak the shirt in cold water with white vinegar
Apply hydrogen peroxide to white shirts only
Use an enzyme stain remover on the affected area
Let the treatment sit for 15 to 30 minutes
Wash the shirt in the hottest water safe for the fabric
Check the stain before drying
Repeat the treatment if the stain remains
Avoid using a dryer until the stain is gone
For white cotton shirts, use oxygen bleach if needed