How do I stay confident advising skeptical or senior clients?

You can advise well most of the time. It is the skeptical ones and the senior ones who rattle you. That makes sense, because those people carry status or doubt, and part of you feels you have to win them over. But their skepticism is not a verdict on you. It is just how careful, experienced people listen. You do not need to overpower a skeptical client or match a senior one's authority. You need to be clear, honest, and steady about what you actually know. When you stop trying to impress and simply give your best true read, the pressure drops. A senior person respects a straight answer far more than a nervous performance. Before your next hard meeting, decide on the one thing you are genuinely sure of and lead with that. Say what you know plainly, say what you do not know honestly. Certainty about the facts, not about yourself, is what steadies you in the room.