The deal is done. Thanks to your skillful negotiation, your company is getting much of what it wanted.  

But don't pat yourself on the back yet. In the excitement of completing the negotiation, those on the other side may forget or misinterpret certain terms of the agreement. As a result, they may not deliver what was promised.

To avoid this potential disaster and wasted time re-negotiating, summarize frequently throughout the negotiation. As soon as you're done, organize and email your notes to key players on both sides, spelling out action steps, responsibilities, timelines and more. Then, if the other party disputes one of the terms a few months later, you've got everything in writing. And should anyone on the other side ask you to modify the agreement, be ready to trade--with an updated wish list.

Remember too that accountability goes both ways (see Tutorial).