I always make sure to have good posture, relax my voice and keep it low, and maintain eye contact (not a death stare but just don’t avoid eye contact all the time). The main thing I think is stay in a good mood and positive when talking to someone and as you appear happy,you’ll appear confident too. I imagine the happy and optimistic characters of my favorite tv shows and sorta copy them. I make sure not to seem to jumpy or overly excited all the time though, just sure of myself and happy and comfortable talking to someone else. Not sure if that helps or makes any sense at all Edit: Another thing, I think people don’t feel very uncomfortable when you stutter, but they do when they visibly see that it is bothering you. If you are talking and you stutter over a word but keep continuing on, and you seem like you don’t care at all and it’s a perfectly normal thing, they will write it off the same seeing that you apparently don’t care too much. If you are tripping on a word and people can tell it’s really bothering you, they feel bad and begin to feel uncomfortable. Basically it’s not your stutter that bothers them, but your own negative reaction to it. It takes some iron emotions and confidence to play of a stutter like it’s nothing though, but I feel like I’ve done it pretty well in the past.