The important thing to remember is that everything of substance has already been written up and will be read by congress members and their staff. Keeping that in mind, the more important object is to make use of the five minutes of microphone time.

I think studying how other people have effectively used their five minutes in instructive. I'd start with the testimony of Fred Rogers where he gave a Senate statement on PBS funding: http://www.americanrhetoric.com/speeches/fredrogerssenatetes...