When someone knocked at the door and a person indoors would say 'Who's that' before opening the door. The reply would be Icky the Firebobby!!
We also heard All my eye and Betty Martin, meaning something wasn't quite true.
She's all fur coat and no knickers

meant someone was putting on a front...trying to be something they weren't.
No better than she ought to be meant a girl who had low morals

Twopence short of a shilling...not quite sane

He's got all his chairs at home meant he knew what was what