Ask what the voice knows that the picture can't show.

Somebody told you that using a voiceover is cheating. That's wrong about half the time. Using a voiceover isn't lazy. Lazy voiceover is lazy, and the difference is easy to test.

Ask what the voice knows that the picture can't show. Goodfellas opens with Henry Hill and two friends finishing off a man in a car trunk, and over it Henry says he always wanted to be a gangster. Nicholas Pileggi and Scorsese aren't explaining the image. They're putting a value on it. The voice admires what you're recoiling from, and that gap is the whole movie. You can't shoot a gap. That's why the voice is there.

Now the version that gets cut. A woman walks into her apartment and the voice says she was exhausted. You already watched her drop her bag. The voice is describing the frame, and a director reading that line sees a writer who doesn't trust the shot. That's what the voiceover people mean when they call it cheating.

There's a third kind and it's the one that saves scripts. A voice that makes a promise. Sunset Boulevard opens with a dead man narrating his own murder, and Wilder and Charles Brackett spend the next two hours making you wait for it. That voice isn't commentary. It's a deal with the audience about where this ends.

If you can delete a line of voiceover and lose nothing, you were captioning. If deleting it changes what the scene means, keep it and stop apologizing for it.