Negotiating has a simple structure but at the same time is difficult to master because it requires a person to think in future tense.
Most people think in the past and present tense when they interact with others and by doing so they set themselves up for negotiation failure. They bring baggage from past interactions and mix it with the heat of the moment which rarely bares a positive result.
Learn To Expect
Learning to improve basic negotiation skill will teach you how to think about future outcomes. It also teaches how to expect certain outcomes in business so you can redirect/deflect them long before they become an issue.