Was told by a mentor of mine a few years back (39yrs ago) some advice that has served me well in situations of conflict resolution and negotiation.
1) Curb you anger and focus on your goal
2)Have a goal in mind of the outcome of any resolution and the minimun result that will satisfy your needs and what is the minimum compromise acceptable to you.
3) Ask clear and concise questions and do not allow the answer to be ignored or left without a commitment of an immediate answer or commitment to one forthcoming in a specific time frame.
4) Always be truthful and use no deception.
GLTUA