Prepare an Organized Speech
To prepare an organized speech means to
work ahead, and think about what you're going to say, so that you won't wing it at the last second. It means that you need to think and note about what you're going to talk about and how you're going to present your idea.
Purpose
The purpose is to make others believe you are well prepared and interested in what you are giving a speech about. Your speech will be more effective this way, and it will be easier for the audience to understand.
How it looks & sounds like
If you do this you will look prepared and less flustered. It will make you sound more confident and less nervous, because you already know what you are going to say. Both of these things combined will make you appear like a professional.
Advice & tips
Think thoroughly about your topic and think about what you can talk about days before your actual speech. Write down your thoughts and ideas. Organize these notes in an order that makes sense, and that will make sense to other people. When giving the speech you will be able to relax a bit more because you will already know what to say.