Those people who intimidate people have lots of experience and have been doing what they do for a long time. That is how they have got to such so expert at doing whatever it is they are intimidating you by doing. Unfortunately, the only way to get more experience in whatever field, is to do more of it. Just put on a brave face and get on with whatever it is you need/want to get better at. Confidence carries you a long way. Act as if you're confident even if you're the furthest from it. It will make your persona seem confident, and in a quick time that becomes how you feel anyway. Confidence gives you authority and though you might not have a clue about what's happening - people will look to you like you do.
It doesn't mean that they are confident but they will certainly look it. And they will grow in confidence because of that. You just have to remember that it's confidence they have, but they're not better than you. Acting the part plays a key role here. You don't have to know what you're doing but if you act like you do people will go along with it. It's all about perception and how others view you.