Start with the idea that you want to resolve the problem, not win the argument.

• No one can “win” an argument.
• Begin in a friendly way. 
• Don’t attack.
• • The more you push, the more the other person is likely to push back

Pick a good time.

• Set an appointment if possible.
• Avoid arguing late at night or in the early hours of the morning.
• Don’t start when you know that one or the other has to leave without adequate time to resolve the problem.

Pick a good place.

• Don’t do it in public.
• Don’t do it in front of other people.

Use the real reason.

• Make sure you understand your real motivation.
• Don’t disguise what you really want to talk about.
• Don’t make the other person guess.
• State your issue in clear terms.

• Don’t say things like “You should know better.” or “You don’t think this important.”

• “He’s your son, you deal with him.”

• No denunciation.
• No character assignation.
• No contempt or sarcasm.
• No taunting.

• Do not get friends, family members or co-workers involved and taking sides.
• Don’t send messages through third parties.
• • “Tell him I think he is being unreasonable.”

• No personalities or comparisons.
• • "You are just like your mother."
• Avoid generalizations.
• • Words like “always” and “never” are not useful because they aren’t usually true.

• Unless it is directly related to resolving the current conflict, let past issues stay in the past.

• Say what you think and feel.
• Don't assume the other knows what you feel, want, need, or what you mean.

• Don’t belittle the other person's accomplishments.
• It’s not useful to try to make the other person feel small.
• Build them up so that they can more easily give in to your point of view.

• “You’re so stupid.”
• “You’re sister would never do that.”
• “Why can’t you be smart like your brother?”

• This could be in the form of a threat...
• • “If you don’t agree with me, I will _________.”

• No intimidating or bullying.
• Speak softly.