Thanks for the question.
Gnostic practitioners can breath deeply and count to 10 in the moment when they are angry. Quiet, sincere prayer is effective as well.
If we want to eliminate anger completely it is not enough to only be aware of it when it arises. We must practice Self Observation at all times in order to see the arising of anger beforehand. To eliminate anger we have to know how it arises.
You may already have noticed that anger is unconscious and habitual. Self Observation will reveal how we feed anger, for example, whether we truly enjoy anger. To eliminate anger requires Repentance. A change of heart. The word that is translated as "Repentance" in the New Testament is the Greek word μετάνοια (Metanoia), which means "a change of mind." The Greek Nóos (“mind”) refers not to our intellect, but to our intelligence, which is located in the heart.
Clearly, to eliminate anger requires a radical transformation of our thoughts, emotions and actions. Replacing unconscious, negative thoughts, emotions, and feelings (actions) with positive thought, emotions, and feelings (actions) is the foundation we build for the Work. A powerful example of this would be, for instance, calling anger "anger" instead of "my anger."
Once we observe the habit of anger in detail, meaning small instances of it (since we are often unconscious during strong instances of anger and have to resort to prayer, breath and counting), a psychoanalytical meditation practice like the one in the link below becomes practical.