What is a good meat-to-breadcrumb-to-egg ratio for meat?

1 lb of ground beef, add 1/2 cup of bread crumbs, one egg, alittle milk, mixture should stay together .. my cooking method is while my tomato sauce is cooking, once I have made the meat I add them straight into the tomato sauce, they come out really moist and you don't get the grease from frying them first in the tomato sauce!