One really good lesson that I learned while taking early childhood education is active listening. This is very important for both teachers and parents.
Have you ever experienced a child repeating something over and over until you answered them? Or in another situation, a child might be feeling sad, but feels better when someone acknowledges how they feel. For example, the preschool teacher could say, 'I understand, it's hard for you to be away from your mom.'
It also works for adults, but in a different way. For example, I was talking to a friend and they were going through a hard time and told me about what happened and how they felt. I looked at the message they emailed me and acknoweledge point by point what they said. For example, 'I agree, it can be very hard when.....'
They wrote back to me saying that I was right on, and then they jokingly said, "It's like your in my head."
The important thing here is that eventhough they still felt kind of down, they felt a little better because of the support from a friend. It doesn't always have to be with words though. sometimes, it could be just listening to them and giving a hug.