I have several consultant friends who are continuing to hold out for the same amount of money they made a year ago, in better economic times.  They are mostly unemployed.  Unless they have more savings than I know about, they have committed perhaps the largest negotiating sin—lack of research.  Research shows that you can achieve the best negotiation outcomes by spending 5x longer preparing for a negotiation than you will actually spend in a negotiation.  My friends have not done their research.  If they had, they would know that consultant pay is plummeting and they have more competition than ever over for their services.  Other major sins of negotiating include: 

• Leaving money on the table
• Walking away from the table when there is a good offer
• Settling for terms that are worse than walking away 

An interesting data point on this last sin: 97% of students in my classes don’t recognize when the best deal is no deal.  After working hard through a negotiation, they don’t want to “fail” to reach one.  They have expended time and effort and want this to be worth something.  It may help to remember that the other side has incurred these same “sunk costs”.