S t e p s
Find out what the other person is interested in. You can even do some research in advance when you know you will have an opportunity to talk with a specific person. Complimenting them is a great place to start. Everyone likes sincere compliments, and that can be a great ice-breaker.
Ask questions. What do they like to do? What sort of things have they done in their life? What is happening to them now? What did they do today or last weekend? Identify things about them that you might be interested in hearing about, and politely ask questions. Remember, there was a reason that you wanted to talk to them, so obviously there was something about them that you found interesting.
Forget yourself. Dale Carnegie once said, "It's much easier to become interested in others than it is to convince them to be interested in you." If you are too busy thinking about yourself.
Practice active listening skills. Part of listening is letting the other person know that you are listening. Make eye contact. Nod. Say "Yes," "I see," "That's interesting," or something similar to give them clues that you are paying attention and not thinking about something else - such as what you are going to say next.
Ask clarifying questions. If the topic seems to be one they are interested in, ask them to clarify what they think or feel about it. If they are talking about an occupation or activity you do not understand, take the opportunity to learn from them. Everyone loves having a chance to teach another willing and interested person about their hobby or subject of expertise.