What is your best negotiating trick?

well the word "trick" does not sound that nice as ioannis previously stressed

Well what i usually did when a customer told me that he was going to buy from another company i was always tried to  make/force him/her in thinking the possible risks s/he would take if left my company. i such a case you build your arguments based in the concept of the "Fear of the unknown" and the "Fear of Loss".people do not like taking risks and changing a suplier would include some risks such as:quality of competitor's products and accompanying services sales personel quality etc, and i always created or recalled "picturer" and tried to bring in surface emotions connected to the pictures. Given that i already had  a good relationship with the customer i would always make a comparison of the good relationship already existed with a possible bad relatioship s/he might have with the prospective  supplier. The basis in this comparison was consisted of mainly "what if" questions

saying that this is my best and final offer is below my budget. for example, if i have a budget of1M, i would say to him that my best and final offer is900K, take it or leave it (after i saw his proposal of1M)

Its always depend on your position for that you should have to work out before use any thing

Prepare about  BATNA  and then bid as per, that time you will have clear view about  to take or not.

Is it really necessary that I should say? ... :p

Never make the first offer (until you are forced to do it). 

At the end, make an offer (price, added value, benefits) that nobody can refuse.

Thank you.

Never "trick" anyone!

Try open up the talk with the negotiater with common grounds of mutual interest. Do not inititae the talks leading to direct deals...let the common platform of need and analysis be in mind. Then as the platform of suffice information is established it becomes more easier to lead the way we want . This is my trick of leading to negotiation.

give the indication to supplier that I've the alternatives & with lower than his price but I prefer his quality & delivery