To begin, take a glass jar or crock(nothing metal) and add:
1 cake (or 1 pkg.) YEAST
2 C warm WATER
2 C all purpose FLOUR
Stir mixture to a smooth thin paste. Put on lid and set in a warm place to sour. Stir it several times a day; the sourdough should be ready in two or three days. (If no yeast is available, add 4 TBSP sugar and 1 1/2 tsp salt to the starter and it will sour, too, except the process will take 5 days.)
To keep starter active, add one cup unsifted flour and one cup warm water and let stand at room temperature either all night or all day. (Do this at least once a week.) Always reserve 1/2 c or more of starter and store in refrigerator.
*I found this recipe in a recipe book called the California Five-in-One Cook Book by Fischer, Al
I always lose these very basic starter recipes, and this one is straight forward and simple