Sure, you don't necessarily know the people in your audience or that new friend in your group, but they're nodding along with you and looking knowingly at you all the same. This means that they are connecting with you. So reward them with your acknowledgment! Use facial expressions consciously. Strive to reflect passion and generate listener empathy by using soft, gentle, aware facial expressions. Avoid negative facial expressions, such as frowns or raised eyebrows. What is or isn't negative depends on the context, particularly the cultural context, so be guided by your situation. Be quick to identify unexpected behavior that suggests a cross-culture collision, such as a clenched fist, a slouched posture, or even silence. If you don't know the culture intimately, ask questions about the communication challenges you might face before you start to speak with (or to) people in an unfamiliar cultural context. Eye contact builds rapport, helps to convince people that you're trustworthy, and displays interest. During a conversation or presentation, it is important to look into the other person's eyes if possible and maintain contact for a reasonable amount of time. Take care not to overdo it.– Use just as much eye contact as feels natural, about 2-4 seconds at a time.  Remember to take in all of your audience. If you're addressing a boardroom, look every member of the board in the eye. Neglecting any single person can easily be taken as a sign of offense and could lose you business, admission, success, or whatever it is you endeavor to achieve. If you're addressing an audience, pause and make eye contact with a member of audience for up to two seconds before breaking away and resuming your talk. This helps individual members of the audience feel personally valued. Be aware that eye contact is culturally ordained. In some cultures it is considered to be unsettling, or inappropriate. Ask about this in particular or do the research in advance. There is power in pausing. Simon Reynolds says that pausing causes an audience to lean in and listen. It helps you to emphasize your points and allow the listener time to digest what has been said. It also helps to make your communication come across as more compelling and it makes your speech easier to absorb and become comfortable with.  Take a few deep breaths to steady yourself before you begin communicating. Get into the habit of solid, regular breathing during a conversation, This will help you to keep a steady, calm voice and will also keep you more relaxed. Use pauses to take a breather from what you are saying. Use hand gestures carefully. Be conscious of what your hands are saying as you speak. Some hand gestures can be very effective in highlighting your points (open gestures), while others can be distracting or even offensive to some listeners, and tend to shut down the conversation or listening (closed gestures). It also helps to watch other speaker's hand gestures with an eye for how they come across to you. Emulate those you see that are effective and engaging. Notice that the most effective gestures are natural, slow, and emphatic. Be alert to your wandering eyes, your hands picking at fluff, your constant sniffling, shuffling, rocking, and the like. These small gestures add up and are all guaranteed to dampen the effectiveness of your message. Have someone record your talk, then take the time to view your speech delivery in fast forward. Any repetitive gesture or unconscious habit will stand out like a sore thumb and will be somewhat comical. Once you have targeted such a behavior, it will be easier to modify your unintended body language and monitor its reappearance.

Summary:
Recognize people. Be clear and unambiguous with your body language, too. Communicate eye-to-eye. Use breathing and pauses to your advantage. Consider how your gestures come across. Keep a check on your other body signals.