Your competition is as prepared as you are. Your competition has rehearsed as had. Your competition knows their material as well as you. So what will give your speech a winning edge? How will the judges distinguish between two or three comparable speeches?
You will give yours some magic! That one utterly unforgettable moment. Deploy something rarely seen in competitions – You might sing but it is difficult to come with something rarely heard -. It could be a prop, a gesture, a stance or a striking way of interacting with the audience.
If the speech competition is stiff, and it will be, it is not be enough for you to leave the judge feeling “That was a great speech.” Instead, you want to leave every judge thinking “Whaaat!, did you see that?”