It's an ongoing process, in the script, on the set and in the editing room, to make sure you are being true to the emotion of the film without turning it into a melodrama, and making sure you're getting all the laughs you can without it turning into just some stupid comedy.
Jon TurteltaubMagic has a spiritual element, and is considered very important and of value, and magicians have always been a little bit silly, so if you're going to portray a modern day magician, there's gotta be a little silliness.
Jon Turteltaub