Building a genuine relationship with another person depends on at least two abilities. The first is seeing the world from another person's perspective. The second ability is being able to think about how you can collaborate with and help the other person rather than thinking about what you can get.
We're not suggesting that you be so saintly that a self-interested thought never crosses your mind. What we're saying is that your first move should always be to help. A study on negotiation found that a key difference between skilled and average negotiators was the time spent searching for shared interests and asking questions of the other person.
Follow that model. Start with a friendly gesture and genuinely mean it. Dale Carnegie's classic book on relationships, despite all its wisdom, has the unfortunate title How to Win Friends and Influence People. This makes Carnegie widely misunderstood. You don't "win" a friend. A friend is not an asset you own; a friend is an ally, a collaborator. When you can tell that someone is attempting sincerity, it leaves you cold. It is like the feeling you have when someone calls you by your first name repeatedly in conversation.
Reid Hoffman, The Start-Up of You