For names, adding a title (ms/mr) right before a name tends to ~fake me out~ and I can avoid stuttering. Also, I add an "ah-" prefix to words to ~bounce off of it~ like in The King's Speech (awesome movie, nifty trick when you HAVE to use a certain word and use it NOW). The best way to fix it is to get a job that requires you to make many phone calls a day. You will cry a lot or go running a lot or whatever you do to manage stress, but you WILL have a breakthrough and develop a more normal relationship with the phone.