The usual method of working is to use the dilute developer (or when it was available - Selectol Soft) first.

The idea is that areas with the most exposure (shadows, dark greys) develop quickly, while light greys and whites do not respond as fast. So, you use a soft working developer to make a full bodied print minus blacks. Then put it into the higher concentrate developer for a short period of time to develop the blacks and add contrast to the entire print.