First off buying and selling real estate is an emotional experience.
Making a deal go together is one thing, keeping it together and getting it financed today is a whole other animal.
Do you actually know the value of what you are buying and or selling?
Knowing the other party you are negotiating with is another relationship to consider, what, who and their motivations?
Convincing the lender of your vision and getting them and their underwriters on board is whole other issue.
Being humble, but firm and effective in dealing with other people can seriously help.
Knowing how to finesse the big and small parts of the entire process can be like a bit of diplomacy.
Keeping your attitude and allowing the whole process to move forward can be everything.
Mastering these steps in having the negotiating will power to follow through is an art form today.