Unique words and phrases and manner of speaking are very nice. I like those. Y'all is a good indicator. And things like darling (or darlin', if the n' is REALLY a must) and other such words can make something feel more unique to the accent. But I don't need the words to be written phonetically for me to understand that they're said differently. Again, unless it's REALLY important, or if you can convey with that one small, unobtrusive difference the differences in the rest of the words.
"Ye might wanna watch where ye put your things. The cats'd like to have a go at that pretty scarf of yours."
Now, I'm not saying MY example is a good example of anything, because I don't know anything about accents. I can't tell you what accent that is except I was going for vaguely UKish, and I'm American and don't know how to depict that. I'd feel like the use of "ye" maybe like, gives the reader a moment to be like, "Oh, this is an accent," and they can slip into that, but it doesn't constantly beat the reader over the head with it? Maybe? Like, enough to remind me, but not enough to try and force feed it to me.