Most people don't want to work with someone else who doesn't bring their A-game each time they come into contact with each other. So, of course, it's important to know what you're talking about whenever you speak on something. Study your craft. Definitely do your homework and do your research on the field you are in. But when you enter into dialogue with people in your field (or maybe in another field you might not be able to call your home), don't try to act like a know-it-all. You might actually know a lot, but you don't have to act like it in an arrogant manner. There is great value in real humility. Let others sing your praises and do the same for others. Also, in dialogue, learn how to ask the right questions. Don't just make statements, but ask good questions. It shows that you are genuinely interested in what others have to say, and that you don't want to hear only the sound of your own voice. People respect that. People appreciate it when others with whom they are conversing are not narcissistic. A good conversationalist knows how to ask good questions and WHEN to ask those questions. Timing is key.
One more thing, listen to people to understand them, not just to respond back. So many people miss the mark on this as they are often in a rush to get their point across and they end up cutting across people when they are mid-sentence. Listen more than you speak. This is something I myself am working on too, because I see the value in being a good listener. Sometimes if you just listen to a person, you will get the answer to the question you have been dying to ask. Patience is another key in engaging people the right way.
When people know you are a good listener, you'll be surprised at how many people will want to talk to you and engage you on a variety of subjects. They know you care about what they have to say and they know you'll make the conversation interesting.
I just want to encourage and inspire as many people as I can for Jesus Christ.