1. Dress properly and comfortably.
2. Have confidence in yourself.
3. Speak neither too fast nor too slow but with composure.
4. Look at the eyes of the people you are talking to but don't stare at them for a long time.
5. Choose topics which can interest both of you.
6. Arm yourself with more meaningful thought.
You can surely leave better impression to others if you do as I tell you.