Emotional validation is a great tool. 

Emotional validation is a great tool for interacting with an emotionally sensitive person.

Listen and be present. Listen and don’t speak right away. When someone is emotional, they want to be heard.
Don’t fix their problem or give advice. They want to be heard, not advised.
Reflect their emotions back accurately. After reading their emotions, reflect them back to the person to verify that you know how they feel.
Focus on the emotions. If they weren’t experiencing strong emotions, they will not be acting the way they are. Don’t get caught up in the practical content. Focus on the emotional context.
Normalize. Relate the feelings to normal people. “I think anyone would be angry if that happened to them.”
Don’t judge. The person will be hurt more if you judge them for feeling the way they do.

Don’t “one up” the person. Don’t say “You think that is bad? What happened to me is worse.” Focus on the current feelings they have, not yours.
Be authentic. Reflect to yourself how you felt when you were angry, sad or anxious.