Patience when they speak is very important at least with my son. And teach that to all in your family as well. Never help those who finish their sentences and never make them feel rushed. I’m sure some may feel differently, but these things have been good for my son. We act like it’s no big deal and he feels more relaxed when talking with us and therefore carries it out to the real world. He’s 15 and his stutter is so minimal now. He’s worked hard to overcome it.