Wet down the makeup stained area of your sweater by running it under cool water in the sink.
Squeeze a little bit of concentrated spot cleaner onto the spot. Work in with a damp washcloth, but be gentle -- you don't want to mess too much with the fibers since they can get fuzzy if you rub too hard. Let the detergent sit on the stain for 10 minutes.
Fill your sink with lukewarm water and pour in a little bit of regular laundry detergent or fine-washables detergent, just enough to make a sudsy bath. Hand wash your sweater by squeezing and turning it in the water.
Remove the sweater from the bath and lay it flat on a large towel. Roll it up in the towel and firmly press the roll to remove excess moisture.
Unroll your sweater and place it on another towel, this time a dry one. Allow to air dry.