Thich Nhat Hanh:

The second function of shamatha is calming. When we have a strong emotion, we know it can be dangerous to act, but we don’t have the strength or clarity to refrain. We have to learn the art of breathing in and out, stopping our activities, and calming our emotions. We have to learn to become solid and stable like an oak tree and not be blown from side to side by the storm. The Buddha taught many techniques to help us calm our body and mind and look deeply at them. The can be summarized in five stages:

1 Recognition—If we are angry, we say, "I know that anger is in me."
2 Acceptance—When we are angry, we do not deny it. We accept what is present.
3 Embracing—We hold our anger in our two arms like a mother holding her crying baby. Our mindfulness embraces our emotion, and this alone can calm our anger and ourselves.
4 Looking deeply—When we are calm enough, we can look deeply to understand what has brought this anger to be, what is causing our baby’s discomfort.
5 Insight—The fruit of looking deeply is understanding the many causes and conditions, primary and secondary, that have brought about our anger, that are causing our baby to cry. Perhaps our baby is hungry. Perhaps his diaper pin is piercing his skin. Our anger was triggered when our friend spoke to us meanly, and suddenly we remember that he was not at his best today because his father is dying. We reflect like this until we have some insights into what has caused our suffering. With insight, we know what to do and what not to do to change the situation.