Scrape off as much of the makeup as possible, using the flat blade of a knife. The edge of a credit card works to scrape off dried-on makeup, too.
Gently rub plain white soap onto the makeup stain. Dampen the area with water, then rub the fabric together. Repeat until the makeup stain is gone.
Apply stain remover to the makeup. Pick one that is specially formulated for grease stains.
Rub the fabric to help work the stain treatment into the material, then let it sit for a few minutes.
Read the fabric tag for specific wash instructions. Following these directions, wash the shirt in the hottest water allowed for that specific fabric or clothing item. Use laundry detergent as well.
Pull the shirt out of the washer when the wash cycle is done and look for any signs of remaining makeup. If the makeup is not totally gone, repeat the stain treatment and wash process until the makeup is gone.