One of the most important things that you need to do before you even get started with handling the talkers at a movie is to make sure that you are not guilty of committing the same crime, as that would make you lose the right of asking others around you to be quiet. If you are in a mood to talk to the person who has accompanied you to the theatre, you are definitely at the wrong place. It is best to simply get up, get out and go sit in a park or at a café. When you are at the theatre, your primary focus should be on watching and enjoying the film and letting others do the same. If there is something really important that you have to say to your companion, wait for a particularly loud scene and quick communicate whatever it is that you want to say to your companion. In other emergency situations, simply whisper, though do not do that too often, as that can get a bit annoying for others who can still hear you.
If you are unfortunate enough to get a seat near a person or group of people who just cannot keep their mouth shut during the movie, politely request them to keep their voice down or maybe even become quiet, explaining to them that you are getting distracted. While you would be saying this politely, make sure you have a stern expression on your face so that the talkers take your request seriously.
If the talkers do not respect your request, then ask them to shush once more, this time far more firmly than before. Hopefully, they would notice that you are beginning to lose your cool and become quiet instead of letting the air become any tenser.
If the movie talkers still continue to talk and become a nuisance, get the ushers involved. Signal for them to come over and complain to them about the people who are constantly talking during the movie. Let them handle the situation from there.
If all else fails, just get up, face the talkers and tell them to shut up. Hopefully, you win get support from others who are also getting disturbed by the talkers.