Get good at enunciation. It's annoying to listen to someone lazily slur their way through saying something. It's shocking how many podcasters are awful about this.
Get good at pithiness. It's more radical to get to the heart of the matter anyway. Don't waste people's time with unnecessary detail, including yours.
Get good at knowing the audience. Tailor your argument to appeal to them, and know when they're unlikely to change so you can walk away and avoid wasting time.