Negotiation

Attended a class on negotiation skills yesterday and today. Among all the rules, I found the following enlightening:
1. Avoid assumptions - there is nothing that is not negotiable.
2. Every time we try to influence others - try to create their needs.
3. Don't underestimate the "Pre" and "Post" stages.
4. Better conserve the concession later.
5. When there is a deadlock, try to identify and expand the common ground, then address the differences.