Here is a little something I found useful when writing dialogue.......
When your creating a dialogue scene, make sure your characters are doing something. Even the nondramatic scenes, have your characters engaged in some activity while they're talking.
From "Dialogue" by Gloria Kempton
This is a tip I used today when I realized I had an entire page of nothing but dialogue. Can you say BORING? Because that is what it was, and repetitive. So I threw one of the characters down a set of stairs and that really livened things up. Don't worry, no one was harmed in the process. Plus it gave me a new story line.