When you know that you are about to stutter, what do you do? What has helped you?

When you know that you are about to stutter, what do you do? What has helped you? I tend to stop, try to say the stuck letter quietly and continue normally once I can say it. It can happen that, when with a group of people, they think I'm not speaking, and talk over me, like I'm not part of the group. But I prefer that over speaking like some freak.