I not an expert in this, but I work with patients who often need help calming down. In the beginning I tried to say a lot of things, offering a different perspective or trying to fix a problem. But now I just try to be there and listen. And not try to fill the silence. Sometimes a calming hand on the shoulder helps, sometimes not. Affirm the feeling and don't argue facts. Last week a patient was upset because she was hallucinating an injured angry dog outside. Instead of telling her she's wrong, I can only say that I myself cannot see a dog, but it sounds scary, and that she's safe here. Another patient said she wanted to die. I think I just said "is that how you feel?" and so but the important part is to be there, just being, without rushing, letting someone feel seen and heard.