I used to tense up very tight as a kid and look weird. I was made fun of for it (on top of the stutter), so I made myself stop. It was mostly just keeping eye contact with whoever I talked to. No matter how uncomfortable. I also NEVER tense up like that anymore. If it’s impossible to get out, then I shut up and breathe. Stop talking entirely. I’ve said so many times “I’m sorry, I can’t talk”. Stuttering was enough. I didn’t need physical ticks as well.