Not sure about common. I guess it depends on who you hang around.
Common Australian Idioms Explained With Funny Illustrations - DesignTAXI.com
The A-Z of Aussie lingo from McCrindle. Lol, I confess I say most of these. :)
Brit Humour: 30 Things British People Say Vs What They Actually Mean - Graphic (Part 1)
You say ‘Straya instead of Australia. | 33 Ways You Know You’re Australian
Australia map made from australian slang words in vector - by lifeofriley on VectorStock®
CUNT. | 9 Outrageous Words That Are Said Every Day In Australia
These are bush Aussie sayings. I'd say they come from the english heritage of cockney sayings when Australia was settled by english convicts.
His and Her Hobbies: His: Living in America - Aussie Lingo
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