The only thing that helps me is when I try to break what I want to say in sentences instead of saying everything all at once. Try this. Speak and sentence starting with an inhale and the speak while you exhale. Inhale with the mouth. When you are approaching a word that you know you will block stop, take a breath and then speak on an exhale. This doesn't cure the stutter but makes it less noticeable. If you get stuck on consonants, try exhaling slowly through the nose and then speaking.