Here's an episode of RadioLab that talks about liars. It's a great example of radio news that keeps the audience interested using only voice, music and sound effects to explain what's happening, even though the viewers can't see it.
STEP ONE - Outline what you want to say.
STEP TWO - Turn your outline into a script. Use the same format as in video projects, but leave out the shot numbers since we'll only hear you, not see you.
STEP THREE - Record it.
STEP FOUR - Edit.