Identify, gather and produce the most important information early. Deal negotiations are most effective at the proverbial sweet spot, when each party has the information they think they need to make a judgment on the agreement, but before discovery expenses allow the sunk cost mentality to take hold. Settlement talks or mediation can give both parties an opportunity to discuss their needs and concerns. Negotiation can pose difficult and emotional problems.
Keeping the conversation polite and respectful will improve your chances of reaching an agreement.