Listen three times more than you talk.
Ask questions. Maintain eye contact. Smile. Frown. Nod. Respond -- not just verbally, but nonverbally. That's all it takes to show the other person he or she is important.
When you do speak, don't offer advice unless you're asked. Listening shows you care a lot more than offering advice does, because when you offer advice, in most cases, you make the conversation about you.
Don't believe me? Who is "Here's what I would do" about: you or the other person?
Speak only when..
..you have something important to say -- and always define important as what matters to the other person, not to you.