Old expressions not in general use.

My Dad often went to see a man about a dog.
We had (I still have) a hot press - airing cupboard.

My Scouse friend says "going to turn my bike around" when she goes to the loo

Gee whizz! (Btw, remember Cheese Whizz?)

Jings! - like Oor Wullie.
I say it but my DH said he's never heard anyone else use it.

Grandma70s mention of 'frightened' reminds me of a story a teacher friend told me. A little lad, who had a broad Wigan accent, put his hand up and said, "Please, Miss, how do you spell 'frittend t'dee-ath?' (frightened to death!)

Two of Nan's regular quotes:
'You look like Annie off the carnoffle boat' (when someone appeared dishevelled).
'I'm saying nothing, but even a monkey has his thoughts.'
East End of London

GIN "Fossilised fish-hooks" is an expression used in the lovely "Jennings and Derbyshire" series of books. I have no idea whether Anthony Buckridge invented the expression or used an something he had heard before.
Did you dredge it up from your memory after reading the books as a child?

My dad would say “Get the big hook” if he was watching something on tv and didn’t like the performance. I think this was before remotes and also before there was lots of choice. I also heard him say “Good gardenstuff” when he was flummoxed or surprised about something.

I lived with my grandma through my teen years, and whenever I was going out and had a belt on fastened tightly, she`d say I was "tied up like a rice bun". That was in Lancashire.

My dad's favourite was 'cheap at half the price'.

One of my Scottish granny’s favourites was “Free, gratis and for nothing”
Another, on punctuality, was to talk of “Falling in with the doors”

"Fine words butter no parsnips"

My late father saw many men about many dogs!

“ Come away in, there’s a gill sent for”, to an arriving guest, and, “ Mind your heid on the lobby lamp”, to a departing one!

Oh, and it was ‘raining in Paris’ when your underskirt was showing!

( In Paris they said, “ Vous cherchez une belle-mère”, which means “you’re looking for a mother-in-law!”)

My nan would describe a woman she thought of as being ‘fast’ as ‘ all red hat and no drawers’ !

Nanny, in DH's family, such a woman was said to be "all fur coat and no knickers"

... and of a women seen as a bit snobbish, or having ideas above her station: "She thinks she's quality street, that one!"

My Sil is from Lanarkshire and has a very colourful (!) turn of phrase. One he uses to emphasise something being immovable/fixed/permanent is “as long as my a* points south”. Don’t know if this is purely a Central Belt saying. My father always used to say “ye gods” as an exclamation of surprise and I still do occasionally.,

If something was very dirty my mother would say 'its black bright '

Many of the phrases already mentioned are very familiar to me... another one used by my late Mum (from Bristol)... if you knew someone vaguely you might say “his cat ran in our passage”

At school we said "It's snowing in Paris" if someone's slip was on show.

"He has bats in the belfry" was one of my Grannie's expressions for anyone who was slightly odd.

Has someone already mentioned "He's no as green as he's cabbage-looking" meaning that someone wasn't as stupid as all that?

If the house was messy, my mother would say it was like ‘ Anneker’s midden’.
I believe Annaker was a Glasgow butcher whose midden (rubbish tip) was often rifled by the poor.

He's all teeth and trousers.

There's none as deaf as won't hear.

I'd rather feed him for a week than a fortnight.

Evil is as evil does.

I also have a dim memory of “many a mickle makes a muckle”.

This thread has taken me back to both sets of grandparents and even great grandparents.

I too remember ‘black bright’ ( only remembered it when seeing sodapop’s post though.)
Grandma used to say ‘now them Dolly Varden’ to me ( a music hall turn?)
I still say ‘gosh’! Does anyone else?

‘Thin as a whippet’ was another phrase.

I've just remembered Mum saying that a neighbour was “no better than she ought to be”. The same neighbour also “thought she was the cat's whiskers” (I don't think Mum liked her very much).

My grandfather would “bet a pound to a penny that....” (something would or wouldn't happen).

In our house, some people were “as thin as a rake” and could be “as daft as a brush”. “Where there's muck there's brass” and “there are none so strange as folks” were other sayings around at the time.

I still say “gosh” or sometimes, to make GC laugh, “oh golly gosh” or “jolly hockeysticks”.