PECBI

When you are preparing to negotiate or deal with a conflict it's best to think PECBI - this will take you through the process from start to finish. 

If it helps to create a table - use these as headings to get you started and keep them updated throughout the negotiation.

Prepare - What is the deal that you want to do? What do you know they want? What has history with this person/company told you? Do you really know what you're offering, is this what they are asking for? What are your known concessions at this point, what are you willing to agree to disagree on?

Exchange Info - At this point usually both parties share their your initial positions, here you can share any concerns, you can focus on what's occurred before to give you setting for the deal, but ultimately use this time to agree on aims that you both share.

Clarify - Get rid of any doubts or concerns, by justifing and bolstering your points with any information and facts. Keep it neutral, positive, brief and factual.  And from the other party get further information about the whys they are holding a position, identify points which are non negotiable - is it their budget? Do they have a time limit or a need to work in a certain way due to restrictions.

Bargain -  When you reach this point, you are going to make a deal, you just need to manage how much you will give away. It's a point to keep emotions under control and not let power plays get in the waty of decent counter offers. Having done your research and understanding what they want will help both of you reach a common ground.

Implement - It's the final countdown. Now your contract should be drawn up or plan to move on from should be agreed upon. Make sure all those notes, concessions and agreed items are included. Don't leave any room to wriggle at this point, you don't want to be coming back to renegotiate!