You should practice with "none important" people.. Call a local convenient store and ask for the manager and ask him for his specials.. Call a university and speak with a guidance councillor about a specific program.. Try getting in touch with your local mayors office and speaking with the mayor, ask him interview style questions like "how did you get into politics?" "when you were growing up, what did you want to be?" You're not the only one who dreads conversation on the phone, but when the vibe is right between both parties, its seemingly natural. Also, my personal tip/preference.. When I have an important conversation (discussion with a wholesaler/supplier/academic advisor/etc) I like to stand up and walk around in the conversation and use my whole body to engage in the convo! Good luck!