Communication implies communing, having a shared experience with another, not "talking at" or "talking down to" someone.
Be clear in your mind what you want the outcome of your communication to achieve. If your aim is more than just to vent your anger towards a meat eater and you sincerely want that person to be a kinder more compassionate being, then you must start by seeing them as a kind and compassionate person. If you are unable to see them as kind and compassionate, then how dare you demand them to see themselves that way.
Be a communicator, not a self-righteous proselytizer or preacher. Many people are only concerned with expressing themselves, which isn't necessarily communication.
