I give piano lessons to my neighbors every Tuesday, there are two 5-year old boys and their 7-year-old brother. There are times throughout the lesson when they will become bored, tired and frustrated. At these points in time I ask the one I'm teaching "Odysseus, what would you like to learn? or, what do you enjoy most about piano lessons?" Whatever the boys answer, I let them know that they are in control and we will do what they like now. Their idea of learning, and fun during piano is a little different than mine; however, I must compromise and give them what they want or else we will all end up unhappy.
Every act you have ever performed since the day you were born was performed because you wanted something. This includes donating $1,000 anonymously to the Red Cross. Why? Because if you found that money was more precious then the feeling of charity, then you would have kept the money.
Since we understand this premise as the foundation of the principle, it is safe to say that whenever we talk to anyone, we are better of talking about what they want, and helping them to get it. So, you can influence, and make a person want to do something by understanding what they want out of a situation.
Find out what they want and truly needed by simply asking "what do you want out of this?"
According to Dale Carnegie, here is one of the best bits of advice ever given about the fine art of human relationships :
"If there is any one secret of success, it lies in the ability to get the other person's point of view and see things from that person's angle as well as from your own." - Henry Ford
Get out there and learn what other want and need.