For me, it's all about knowing what you can and cant say. funnily enough I can't say the word stutter. So I replace it with "speech impediment" or "stammer". I find myself doing this whole sentences in front of what I'm actually saying. I'll "scan ahead" in my brain to what I'm going to say, work out what words i'm going to have trouble on, replace them with words that I can say. This sometimes means that I have to re arrange the entire sentence on the fly while still talking. It get's a bit messy but the one good thing about a stutter is that I'm practically a walking thesaurus now.