I usually say, “yes” when I answer a phone because I have a hard time saying hello. It also helps if I change my tone. Acting lazy or tired helps me relax as well, especially when I’m stressed over a call. The biggest thing that helps me though is taking sips of water before the start of a sentence, followed by deep breaths in through the nose and pursed lip breathing out through the mouth. I try to extend the exhalation as much as possible to empty out my lungs. I feel like air trapping in my lungs is part of what causes my stuttering.