I mean, no technique is perfect. But I would say it stopped 90 of my problem. I have a very out there personality. So singing (or at least just pretending to) really helped me open up even more. I've been doing this for 3 years and it's kinda weird to use both sides of your brain at once but it's really awesome now. Like I said before, I'm very out going. So if I do mess up in interviews I usually just laugh at myself. People are more likely to forget and laugh WITH you when you laugh first. Oh and learn to laugh at yourself.