Spontaneity is certainly better than planning every word. For job interviews I never plan exactly what I'm going to say. I'll prepare relevant things to talk about but not how I'm going to phrase them. This combined with the fact I generally don't care how the interview goes or if I get the job reduces anxiety to a minimum, and I don't stutter much (although a lot of other things are at play which have increased my fluency). I'm not sure I'd call 'trying not to stutter' a technique though. The other side of the coin is 'trying to speak fluently'. The focus may be different, but both draw on numerous resources to achieve the goal.