Turn their frustration and anger into laughter. Example: A mother comes home from a several day trip without her child. The child is angry for her leaving for so long. What does the mother do? She grabs her and starts tickling her to make her smile and laugh. You know what works for your child so do what is needed to turn the frown upside down.
Sometimes even just moving closer and giving your child eye contact can help your child let go of angry feelings, according to author Kate Orson who wrote, Tears Heal. In her experience, yelling at a child and taking toys away are less effective.