I answer the phone everyday at work at least 15-20 times. everyones different, but for me counting down in my head from 3, starting to breathe out, and attacking the call with confidence seems to help. I have had customers make fun of me on the phone as well. best to just brush it off. at the end of the day you are on the phone, they can't see you, they don't know you, and you're there to make money. be confident and do your best.