For the best video on Zoom: go to Settings > Video and check "HD" to enable 1080p or 720p (requires 3+ Mbps upload). Enable "Touch up my appearance" for a subtle skin-smoothing effect. Turn on "Adjust for low light" if your room isn't well-lit. Set your camera to be at eye level and about 2 feet from your face. For the Virtual Background feature to work well, sit in front of a plain wall and have good lighting. In advanced settings, uncheck "Mirror my video" only if text in your background needs to be readable (your video is mirrored to you but not to others by default). If your webcam has its own software (Logitech Tune, etc.), set white balance to Auto, increase sharpness slightly, and ensure autofocus is enabled. Close other apps to free CPU resources for video encoding.
Sources