“A man said to the Prophet, ‘Give me advice.’ The Prophet, peace be upon him, said, ‘Do not get angry.’ The man asked repeatedly and the Prophet answered each time, ‘Do not get angry.’”
Related by Bukhari & Muslim
This hadith signifies how important it is for us not to be angry, angry causes all sorts of irrational acts and as a Muslim we must realize the petty nature of most things that gets us angry. We should always remind Ourself weather or not his anger is worth it ,when being weighed next to pleasing Allah. We must also keep in mind that as Muslims we must stay away from those things that usually leads us to being Angry,and also not to act upon our anger when we get angry. Instead he should follow those means that will extinguish our anger such as taking wudu laying down, reading the quran by restraining our angry we are reducing the chances of the guilt later that may arise.
Patience is the keys by friends. Good things happen to those who are patience

As the prophet swc use to say as a ducaa Asaluka kalimata haqu fii radaa waal qadhaabaa- In other words I ask you for truthful speech during the times of pleasure and anger
As during the times of anger people are unable to control there tongue.Many times they will even lie simply out of anger.hence, the prophet made this supplication so that his followers will do the same