Master your topic area. Familiarize yourself not just with the arguments you plan to make, but with those likely to be presented by the opposition.
Rehearse with friends or teammates, using the same format and time limits required in the formal match. In rehearsal, try arguing the opposing side''s point.
Familiarize yourself with common errors in reasoning such as weak inductive reasoning-all the cars at this gas station are blue; therefore, blue cars are the most popular in this area-and "straw man" arguments, both to purge your own argument of them and to spot flaws in your opponent's logic.
During the debate, listen carefully; don't get so involved in planning your rebuttal that you miss an important point. Breathe deeply, make eye contact with your audience, use confident body language, and project your voice If the issue is one you have strong personal opinions about, put them aside-neither opinions nor personal attacks help to win debates. Politeness is an absolute requirement.
In making your case, clearly define each of the points you make. Make it clear to your listeners when you are introducing a new point, i.e., "Yet another point clearly in favor is ..." rather than "Also ..." Back up each of your arguments with factual evidence. Avoid opinion.
Note all of your opponent's key points and offer the strongest possible rebuttal of each one in turn.
In your final summation, begin with the common ground shared by both sides, such as "We would all like to see poverty eliminated." Briefly restate and rebut each of your opponent's key points. End with your own strongest argument.