Look, British English is a problem all of its own. Between saying cheerio and looking like a dog's dinner, there's a high chance that foreigners will have absolutely no idea what's going on. But if you start to go into regional dialects, as you will have to do if you live in the British Isles for any period of time and meet more than three people, it becomes downright mystifying. Some idioms are virtually unknown outside of their own county (the equivalent of a state), others are more widespread — but the expression of utter confusion they put on my face is the same.
I'm not unfamiliar with peculiar expressions. I'm Australian, and we think to say somebody's got "roos loose up in the top paddock" is a perfectly normal way of saying they're not all there upstairs. (My favorite Aussie expression is "we're not here to f*ck spiders," which is what you say in response to an incredibly obvious or stupid question about what you're doing, closely tied with "stop being a sook," meaning stop being a sentimental mess.) But the English do it with a flair that comes from centuries of regional difference and hilarity, and that's not even getting into the wonder of astonishing vocabulary that is Cockney rhyming slang (some of which made it to Australia in the '20s, so I know that a "loaf of bread" means your head, obviously).
If you get to spend some time among Brits, you'll be blessed — and likely also slightly puzzled by what on earth they're going on about. Friendly hint: if somebody says they want a cwtch, rhyming with "butch," they're after a hug, and are also Welsh.
1. "To Bung Something"
2. "To Be Made Up"
Region: Possibly from Liverpool, but we're not sure
3. "Every Little Helps"
5. "Pro(p)er Job"
Meaning: If you thought this was going to be something affectionate about the nature of dogs, you'd be wrong. This is a widely-used but pretty archaic term for anybody who does somebody else's really unappealing work for little reward — a servant, an intern, or somebody really low down the pecking order. It comes from the Royal Navy's term for the lowly sailors doing work nobody else wanted to do.
7. "Mad As A Box Of Frogs"
8. "Damp Squib"
Meaning: This sounds weirdly sexual, but it isn't. It's often used to mean something like a "wet blanket," or somebody who spoils the fun of a party, but actually it means something a bit more complex. A squib is an old-fashioned term for a firework, and a damp one wouldn't go off — so technically a damp squib is something that promised to be magnificent but was just a letdown.
Region: Shropshire, Staffordshire, South Yorkshire
11. "Bishy Barney Bee"