Check out this book by Haim Ginott.
Between Parent and Child: The Bestselling Classic That Revolutionized Parent-Child Communication

I have come to a frightening conclusion.
I am the decisive element in the classroom.

It is my personal approach that creates the climate.
It is my daily mood that makes the weather.

As a teacher I possess tremendous power
to make a child's life miserable or joyous.
I can be a tool of torture
or an instrument of inspiration.

I can humiliate or humor, hurt or heal.
In all situations, it is my response
that decides whether a crisis will be escalated or de-escalated,
and a child humanized or de-humanized.