My Georgia Grandmother would say, when one of the cousins was acting ridiculous, “That boy ain’t got the good sense God gave a cucumber*.”
*pronounced cucumbah
I missed this thread the first time around-- hilarious! My father was from east Texas and my late husband was raised in south Texas, so many of these expressions are familiar to me.
How about “slicker 'n greased owl shit.”
For a homely face: “Looks like someone set their face on fire then put it out with a track shoe.”
“Lower than a snake’s belly in a wagon rut.”
“Busier than a long-tailed kitty in a room full of rockin’ chairs.”
As for calling women “Miss <First Name>,” I hear that (and say it) all the time. At the doctors’ office, the hairdresser, clerks in stores-- as soon as they note my first/last name, they opt for “Miss ThelmaLou.” Maybe in professional settings, it’s a compromise between the still proper “Mrs. <Last Name>” (or Miss/Ms.) and the too informal first name by itself. “Miss ThelmaLou” is somewhere between stuffy and overly familiar?
When I worked, the women in the office also addressed each other as “Miss Mary” or whatever, whether we were peers or older/younger. It was light-hearted and just a little tongue-in-cheek. I worked in the non-profit field, so we’re not talking about Fancy Law Firms or Fortune500 companies. Maybe not used every single time you addressed someone, but often, “Hey, Miss Thelma, y’all ready for lunch?” Even one of my girlfriends calls me this. It’s a little puzzling, as this practice was not prevalent my whole life. I’m trying to remember when it started… maybe within the last 20-ish years?
The song “Green Grow the Lilacs” appeared in the 1956 Disney movie “Westward Ho! the Wagons” starring Fess Parker. I can sing it for you. 
From IMDB:
ETA: Looking at the cast list-- LOTS of original Mouseketeers!
Slicker’n deer guts on a pump handle.
Slicker’n two eels fuckin’ in a barrel of snot.
Some of my late Other Shoe’s relatives lived in the Texas Panhandle. The saying I liked best was for, when things were going exceptionally well: “Now we’re shittin’ in high cotton, and wipin’ our asses with the tallest stem.”
He was so dumb he couldn’t pour piss out of a boot if the instructions were on the heel. Southern Ohio.
Dennis
“Dumb as a box of hair”
Put the laundry on the divan. Divan = couch, sofa.
Get a tea towel and dry these dishes. Tea towel = kitchen towel.
Why come you did that? Why come it’s raining when sun was forecasted? Why come = how come, why, why did.
I like to never found the Ovaltine at Walmart. Like to never = almost didn’t
I have loved reading through these, and had to add some from Oklahoma.
Also, would you like some sweet tea? Sweet tea = ice tea, iced tea, ALWAYS sweetened of course.
And haha, I remember asking my 5th grade teacher how to spell “wallago,” as in: I fed the dog a wallago. Or: Wallago, I was watching tv and the tornado siren went off. … (A) While ago. 
Mott-toe and ought-toe, for motto and auto. And Dia-beet-tease.
Lemme guess, southeastern Missouri?