Audio quality is the second most important factor after Internet connection quality. Use a headset (headphones with built-in microphone) or high quality microphone to make sure your voice is clearly heard. Research has shown that presenters with higher quality audio are perceived to be smarter and more likeable! 
Wireless (especially Bluetooth headphones, including AirPods) increase the time it takes for you to hear and respond to the active speaker. This additional delay makes it harder for everyone to know when it's their chance to speak. Use a wired device to make sure that everybody has a good conversation experience.
Placing your camera at eye level lets people see your face at a natural angle and not up your nose or down at your forehead.
While the exact number is still up for debate, a big percentage of the information conveyed in a conversation is nonverbal — things like facial expressions, hand motions, and body posture. Your ability to show and understand feelings is severely impacted when these nonverbal cues are not there. Also, when your brain does not get these nonverbal cues during a conversation, it works extra hard to fill in the void, leaving you feeling tired and drained. Make sure you're well framed so energy levels stay high for everyone on the call.
Similar to keeping an arm's length distance from your camera, moving your video window towards the top of your monitor reduces the angle between your eyes and the camera, making it easier for you to make eye contact. Also, looking at larger faces tells your brain that you're engaging in a more intimate conversation. Shrinking the video size will help your brain relax a bit.
Stay in touch for more research-based info on how to look awesome in your video calls.
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