On of the things that Bryan Post discussing is the need to bring your kids into "Relationship" with yourself. A big part of that is developing a state of being where you rarely (if ever) lose your cool and move into a reactive place.
A child who has never really experienced trauma naturally feels safe with his or her parents even when they get angry or upset. A Child of Trauma immediately goes into fight, freeze, or flight when a parent moves into a reactive mode.