I've noticed that, like another commenter said, being slightly distracted helps me while on the phone. I can't just be only concentrating on a phone call, I have to be doing something else, like driving, drawing, writing something, etc. Be careful with driving though, because it might lead you to be too distracted. Also, be sure you're in a place where you're comfortable. I'm often very uncomfortable in my house, because I know other people are listening to my phone call, so I make sure I'm in a place where I don't feel like I'm being listened to by outsiders. Also, I hate having a phone up to my ear. It gives me anxiety for whatever reason. Only hearing someone in one ear is quite annoying to me, too, so I often use my earbuds to have a phone conversation. That way, I can hear them better, and also don't have the phone up to my face. Writing down what you might need to say would also be worth trying. I sometimes have to write out phone calls if I'm feeling particularly nervous before hand. It helps to read something as you're saying it sometimes.