Start writing your cards where you know what will be said...
This means the introductions, definition, beginning of responses and so on.
You know that theses do not change and so you can be pre-prepared.
"Good evening, Ladies and Gentlemen and Mr. Chairman. The topic for tonight's debate is..... . We, the affirmative team believe that this is true. We wish to define the topic as meaning..... "
All of these sections are in your booklet and should her used every time. Be prepared early