People fight for several reasons. One of which is insecurity. When a person gets their feelings hurt they strike out creating a problem between the two persons if the other person isn't big enough to handle the criticism. Many people fight because someone is being judgemental about another. Misunderstandings also create many fights. When you misunderstand a comment or an action and respond in a negative way it can cause a fight. Taking offense to someone or something and not having self control over that feeling is another way to get into a fight.
In order to get what you want you need to think it through for the best approach and never ever lose your temper.