Make the other person happy about doing what you want or need them to do.
People will work a lot harder and produce much better results if they are happy with what they are doing rather than resentful. So, make them happy about it!
Don’t promise anything that you cannot deliver. Forget about our own benefits, and instead, focus on the benefits to the other person.
Think carefully about what it is you want the other person to do.
Ask yourself what it is the other person really wants.
Consider the benefits your interlocutor will receive from doing what you suggest.
Match those benefits to the other person’s wants.
Form the request in such a way that will convey to the interlocutor the idea that he personally will benefit.