This tip isn't just for stutterers. First, a rehearsal with a friend, and film it and watch it. And then another one in front of someone you kinda fears? Like for example if you have a strict father... The first rehearsal is to know how your interview goes when you do not feel anxious, to know what's possible when your anxiety is at minimum. The second one is to know how you look when you feel judged by your Darth Vader. Watch the footage to check for your stimming, tics, secondary behaviors, body posture. For example, if you discover that you still grimace during your blocks, now you know to disclose that in the beginning of a real interview. If you discover you smirk when anxious, now you know to do something about that.