Y'all forever. One of the few southern mannerisms I intentionally don't drop as a lapsed southerner in California.
As an aside, I find it strange how many aspects of "the south" are labeled as "Texan" outside the south. I lived and visited all over the Deep South and y'all was standard vernacular pretty much everywhere. I'm not saying Texans don't say y'all, but they definitely don't have any unique claim to using it as second-person plural.
I grew up mostly in the north and talk very northernly, but somehow the only exception is that 'howdy' became my standard greeting. 'yall' feels like too much, but 'howdy' just rolls off the tongue so smoothly. Other greetings always sound too terse (hi, hey), too formal (hello), or are questions (how's it going, what's up) which I just loathe. Though technically howdy is sort of a question too, coming from 'how do you do'.
What's 'a piece'? Don't think I've heard that one.
As an aside, I find it strange how many aspects of "the south" are labeled as "Texan" outside the south. I lived and visited all over the Deep South and y'all was standard vernacular pretty much everywhere. I'm not saying Texans don't say y'all, but they definitely don't have any unique claim to using it as second-person plural.