Here are a few general tips for presenting a WINNING persuasive speech:
Keep your message SIMPLE
Don't leave your audience wondering what you are trying to persuade them of!
State it clearly and concisely: This is what I aim to persuade you of and this is how I'm going to do it... (without using these exact words... that would be boring...).
This is easier said than done! Especially when you are feeling nervous.
Focus on your breathing and remember to do some visualisation exercises.
The energy you exude will be reflected in the reaction of your audience - if you come accross as half dead, the audience will be feeling the same!
Give people time to process what you have said between each argument.
Vary your INTONATION
Your intonation is the "music" in your voice - it is what makes your voice interesting to listen to!
Nobody want to listen to someone who speaks in exactly the same tone of voice the whole time...
There will be 10 or 20 or 100 other speakers who will be speaking about the exact same theme you are, so be different!
Be unexpected, be unique, be the speaker and speech everyone will remember!
Even if you have to shock a little or be funny to be remembered.
START STRONG and END even STRONGER
Most people will only remember the beginning and end of your speech (except the adjudicators obviously... ), and that is IF they remember anything, so it is extremely important that your INTRODUCTION and CONCLUSION be very impactful.