I discovered that I usually stutter in unfamiliar situations. So I try to take a few seconds to find smth comfortable in the situation I am ("yes, I weren't here before, but I know how the job interview are conducted in general", "yes, I don't know this saleperson, but I was here last week" ) Also reading aloud at home helped me a lot: i usually can read fluently and this arises my confidence, I try to choose book I really like for this