This helps me too, and just focusing on calm controlled breathing techniques before you start a sentence, as well as breathing during a natural pause during speaking too (I tend to hold my breath and contract my diaphragm when I speak, which makes the stutter worse when a difficult word comes up). When I was speech theraphy another useful technique I learned was to say "one-one-thousand-and-one" in your head before starting a sentence. If you say it in your head really slow, connecting the words together in a fluid way, the word you say out loud after the last "one" comes out a lot smoother. This helps me a lot when I need to make a phone call, or when I know it's my turn to speak:)