Create a team on your side. It may consist of co-negotiators, experts in various aspects or good cop-bad cop, information sources, and devil’s advocates with whom you can role-play. Practice before you go to the table.
Assess the other side and the members of their team. Who are their decision makers? Don’t get caught by a higher authority. Strategize. Do you want to control the negotiation or let the other side control the flow? Do you want to lead from strength or react to a lead from the other side? How many face-to-face meetings do you want to have? No answer is right or wrong. That depends on your needs, your goals, the tone and style of the other side, timing, and egos.
Plan you concessions. Where will you give in? Where will you stand firm? How will you make a move so that it gives the least and gains the most? Write out/set forth you proposals in advance – test them, state them, and restate them until you are comfortable.
Don’t stop practicing until you are comfortable. Don’t stop practicing until you are comfortable that your strategy works and flexes when faced with a variety of opposing strategies.