If you are still trad. knock on doors of houses surrounding present customer, with bucket in hand, and ask if they can fill your bucket up, as the house you are cleaning, customer isn't in.
Quite often they will ask you, how much you charge.
Also, wash out your scrim, whilst standing at the front of house, in full view of rest of street, any neighbours looking out their window, will be impressed that you are going to use clean scrim, and might well ask for a price.
Blessings,
Graeme