Sound first: it is what gives you away

If you only get to improve one thing: the sound. A viewer who thinks the picture is mediocre stays. A viewer who cannot hear what you are saying swipes.

Why the phone microphone rarely suffices

It sits an arm's length away and picks up everything in between: the room, the fridge, the traffic. The further away the microphone is, the more room and the less voice.

Three things that fix most of it

• Get closer. A lavalier on your top, a handheld microphone just out of frame, or simply a shorter distance.
• Kill the room. Soft surfaces eat echo. A room with a sofa, curtains and a rug sounds better than an empty kitchen.
• Switch off anything that hums. Fan, tumble dryer, ventilation. You do not hear it while filming. You hear it in the clip.

Listen before you film everything

Record ten seconds, put on headphones, listen. It takes half a minute and saves a whole shoot.