Book
Three things help in optmising in negotiations

The book You Can Negotiate Anything by Herb Cohen is a classic to learn to negotiate. Small business owners have less leverage as compared to big businesses. This book shares a blueprint for successful negotiations.
Information, time and power can tilt the balance in the favour of the negotiator. If the other party commits time and resource, one can start to negotiate from the position of power. Asking someone to explain the product or service is a tactic to make others commit.
Power comes from various sources. Power of competition is when one can negotiate knowing there are competitors. Power of legitimacy makes people believe. Power of precedence helps in asserting during the negotiation. Willingness to take risks, ability to draw commitment, expertise and morality also help in drawing power while negotiating.
Knowing others’ deadline, while not disclosing yours will always give you an upper hand. Vietnam negotiated with USA for two and half years, knowing they had a deadline.
Information is a secret weapon. Ask as many questions as possible. Gather as much information as possible about the product, brand, industry and the economy before negotiating a deal.
Learn to negotiate for a mutual win and not win at all cost approach. Showing dignity of the other party is always helpful. Mutual satisfaction leads to successful negotiations.
Book: How To Negotiate Anything Link