In old times, servants of kings and queens always had to have a mirror, because whenever anyone was presented to the emperor, they had to be perfect in their appearance. So for the sake of formal etiquette, people would carry a pouch with a small mirror inside. Try it. Carry a mirror with you and look at it to see what state you are in. After you have breathed in and out a few times, smiling at yourself, the tension will be gone, and you will obtain some relief.
— Thich Nhat Hanh, Anger