My son when he was 4-5 years old started to stutter. I was alarmed and remembered to soothe him like this: when you feel the words are hard for you to say, you stop and touch your cheek or chin and you will touch them as you speak. Stopped stammering.
It may have been a mere coincidence but then I saw the movie "The King's Speech" and the therapist also seeks to introduce a distraction so that one does not focus on stuttering.