For my ocs, I have unique body language and unique dialogue tags for very specific characters that do not repeat to other ones.
For my main oc in my fan fiction (Siorc) since he has selective mutism I use the following unique dialogue tags on him, only:
autonomously (the Kantian philosophy of it being moral obligation not desire),
voice/words barely audible. I gave him unique body language in that he jumps a certain amount of steps back, as well, when he's nervous, and the amount he jumps back is the how nervous he is at that particular point in time.
And then I do some other unique dialogue tags for my other ocs, such as specifying the speed of the words for my panda oc, Yinlong, specifying if there's a graceful tone in my gazelle oc's voice, Parisa, and, "his words were exaggerated/tone was exaggerated/let out an exaggerated gasp" for Kaiser.
Some of my ocs have pet word/pet nickname speech when they talk, and say either, hon/honey. While some of my ocs have specific coded body language, like slamming their fist onto their other hand, their ahoge twitching about, or having specific verbal tics, like saying
you flea/leech/moth/butterfly. I try to have all my ocs have either unique dialogue tags or body language that only applies to them so every single one of them is different from one another.
Even though I always do descriptive dialogue I make sure that each of my characters has something that sets them apart from each other.
For canon characters, I try to keep them to feel as in character as possible, but I take it a step farther and use their body language when they talk. For example: Tartaglia from Genshin Impact crosses his arms when he talks, then places his left arm on his left hip. I find body language in dialogue very important to differentiate characters from eachother, so I try as much as possible to include this in my stories. I'll post an example below:
"Ah, you're the one who wishes to spar with me?" spoke the Eleventh. There was a high amount of confidence in his voice. "I'll take you on."
The hyena sighed as the Eleventh made his presence known to him. He knew from a multitude of stories that the Harbinger was battle hungry, the early adult lowered his bespectacled eyes into a glare. Had this man missed what Her Majesty said entirely? What an absolutely ludicrous person in front of him. Today would not be a day that would be enjoyable in the slightest.
Fatui glaring at him, the eleventh rubbed his hands through his brown spiky hair. Had the soldier taken his small joke seriously? How incredibly strange.
"Haha, kidding," the eleventh spoke again. "You wanted to train, right?" His left hand had been placed upon his hip as the correct statement was released.
(I'm not a conventional dialogue writer, bear with me.)