How do you make phone calls less awkward?

I don't know if it's just me but being on the phone with anyone other than my friends, parents or girlfriend is awkward as hell and sometimes nerve racking. Whether it's ordering takeout, calling customer service, calling my school to ask a question, or even wishing my family members happy birthday it's always awkward and I don't know what to do. In person, I have no problem talking to anyone but over the phone I have no idea what to do or what to say.

So, how do you do it non socially awkward people?