Listen carefully to what everyone is saying.
Try to speak clearly and calmly.
Take turns when speaking, don't interrupt the other person or speak over them.
Write down the points to which you need to respond so you don't forget them when it is your turn to speak.
Make sure you understand exactly what is being said and ask questions if you don't understand something.
Maintain appropriate eye contact with the person you are talking to.
Remember the other person might be feeling emotional and that how you speak to them might affect how they feel and how willing they are to compromise with you.