The Preliminary task

Shot reverse shot: It's a shot of two people and there is a couple of over the shoulder shots and then it goes back to the two people.

Match on Action: If someone walks through the door it will quickly change to the person coming out of the other side of the door.

180* Rule: You have two people and they are only allowed in half of the area around them which is 180* so it doesn't confuse the audience.