Beware the talking heads.
Another way to say this is, ground your characters in their scene. Notice the complete lack of background in the above photo? Lots of times I read a scene in a manuscript, and it's the same way. Two people are talking back and forth, but I have no idea where they are or what they're doing.
Having your characters interact with their surroundings can show a range of emotions (like kicking a chair in anger or nervously picking at sweater threads), and it can give some much needed breaks between speeches.
So, keep your characters grounded in their scene. In fact, let your setting BE a character.