Answer: Having evidence of the situation/thing you are talking about, knowing what you say and speaking carefully, and remaining calm at all times.
Explanation: Some components that are necessary/important in creating a strong argument are having evidence to back you up in your statements, knowing what you will say beforehand, and not getting angry because that shows that you aren't focused on what you are statting, and most importantly, knowing how to speak to not hurt/harm/offend the person you are arguing with. This shows that you are calm and more professional with how you are.