Pupils form impressions of online lessons within seconds. Poor audio is the single biggest predictor of disengagement — far more damaging than a slightly fuzzy camera. Invest in a basic USB microphone or a wired headset before anything else; built-in laptop microphones almost always sound muffled and pick up keyboard noise.
Position your camera at eye level. Looking down into a webcam makes you look distracted and authoritarian; looking up looks unprofessional. A stack of books under the laptop fixes this for free. Frame yourself from chest to just above your head, with light coming from in front of you (a window facing you, not behind you).
