1 bar Ivory Soap (or 2/3 bar Fels Naptha)
1/2 cup Borax
1/2 cup Washing Soda (found in the laundry aisle).
Grate 1 bar of Ivory soap (or other not strongly scented bar soap).
Add 1/2 cup of borax.
Add 1/2 cup washing soda.
Mix together and store in air tight container.
Use 1-2 tablespoons per load.
Both recipes are for a low-sudsing detergent and work especially well in high efficiency washing machines.