A few old southernisms I remember from my Mama:
Do your best. That’s all a mule can do.
Don’t get your britches in an uproar. (Meaning, “simmer down.”)
You’re trying to pick the fly specks out of the pepper now. (You are making too fine a point.)
The sun doesn’t shine on one dog’s ass all the time. (I would have said “The sun don’t shine…” but my mother, while not above saying “ass,” would never have used poor grammar. She was a teacher.)
In As Good As It Gets Melvin Udall (Jack Nicholson) tells a Jewish couple who have the nerve to be at his table when he wants to sit there “Guess your eyes were bigger than your noses”.
I’ve heard this one many times, and sometimes “the sun doesn’t shine up the same dog’s ass all the time”.
I’ve heard pretentious people referred to as “tryin’ to shit higher than their asshole”. I’ve also heard “Mules in horse harnesses” but I think that one came from the movie Gone With the Wind more than passed down. “Cadillac hubcaps on a Chevy” has a similar meaning.
“It’s a sorry dog that won’t wag it’s own tail” means “sometimes it’s okay to be immodest”.
“Josie’s puppy’s too damned smart”- I’ve no idea who Josie is or was, but this is used when somebody is always bragging on their husband/child/somebody in their family until everyone’s sick of hearing it.
That one can also mean that someone is generally kinda crazy. “You know Sam’s touched (or tetched) in the head.”
I’m totally going to use “dumber than a hundred chickens.” I’ve always used “dumber than a box of rocks” or “than a bucket of hair.”
“I’m feeling peaked”. The word peaked is stretched out into two syllables: peak-ed; and the “ed” is sounded just like the name Ed.
MDSL: try “dumb as a sack of hammers” or “box of mud”.
If you’re really hungry: “my stomach thinks my throat’s been cut”. Or “I could eat the ass end out of a mule”.
“Well butter my butt and call me a biscuit!”. My bff from home says that one.
Actually, it’s “How much more you got to eat? Appetites aren’t as big as your noses, huh?”
I grew up hearing this one as “I wouldn’t piss on his ass if his piles were on fire.”
Of a pretentious person it might also be said: “He thinks his shit don’t stink.”
Which reminds me of this one:
“He looks like the north end of a southbound mule.”
My mother used to say “I have to piss so bad my teeth are floating”.
Grandpa was fond of saying “Colder than belly-blue hell”. I have no idea what/where belly-blue hell is, but it sounds pretty damned cold!
I’m from southern Indiana and have heard MANY of these thru the years.
Yeah, I put that one in the “insults” thread.
Which is similar to one about being hungry I’ve always heard:
“I’m hungry enough to eat the north end of a southbound skunk.”
Also, someone who’s touched can also be “nuttier than squirrel shit” or just a general “squirrel bait”.
And I heard it as “I wouldn’t piss in his ear if his head were (was) on fire.”
A friend living in E. central KY once told me that “that dog won’t hunt,” meaning that what I had suggested wasn’t going to work. I’ve tried to use that once or twice, but I’m a city boy so it just goes sideways on me. Another one I used to hear around here was “tumped over,” meaning something was turned over. Friends of mine would go to the “the-8-ter” to see a movie. I’ve also heard “All y’all” or “All of y’all” used to address a group of people. The biggest one around here is how exactly one pronounces my hometown:
-Luhvull (properly pronounced only by natives or long-time residents)
-Louahvull
-Looeyville
-Looaville (used by terminally excited radio announcers and is a travesty)
-Looisville (used by folks who have never been here).
A sure sign of a native (or near native) Luhvullian is to
A) ask what high school you graduated from,
B) when giving directions, mention going to, past or turning where X used to be, even though X ceased to exist decades ago and
C) ask if you are going to the Oaks this year?
My Daddy was raised in Bowling Green and Louisville, and he pronounces it Luhvull, just like you say.
He’d say things like “You don’t know any more about that than a wild hog does of Christmas”. And if you were late to supper he’d say “We thought the hogs had et ya”.
A Mississippianism you don’t hear much any more is “triflin’”. “That’s just triflin’, Suzanne”.
Which reminds me. If my sister and I slept late as teens, my dad would accuse us of “layin’ up like a bunch of wild hogs”
Two my father used to say:
“I’m tired of his asslin’ around up there”. (I think it’s a contraction of “ass laying”- it meant sitting around doing nothing.)
“Woman’s got teeth like the devil’s shit rakes.” (Bad teeth, obviously.)
Everybody used “cocked up”- “She’s laying cocked up on that sofa like a queen” or “He’s sitting cocked up there at his house while she’s out working”.
If you will look back at post #102, you will see that I have accused you of this very thing. 
(Spoke started it at post #99).
Daddy… is that you???
A good ol’ country boy I used to work with had a whole mess of sayin’s. I can only think of a couple right offhand.
“Happier than a puppy with two peters”
Bad luck: “I could fall into a pool of nipples and come up suckin’ a thumb.”
I live in Texas but my family comes from rural Alabama and a lot of these are giving me flashbacks. I remember my Grandma used to call us “chilluns” and “towheads” and referred to our toys as “play purties”.
As to being sent out to fetch a switch, I remember my dad saying it was a rookie mistake to go get the a small thin one. They’d cut and sting a lot worse than a more substantial one.
“Like hell after a yearling”- absolutely no idea other than it means “diligently after something”
My grandfather on my grandmother: “She’ll travel three times around the world to wind up on a back alley”.