If it's an 8 minute speech then that's probably about 10 points. Start by memorising each point. Give it a one word title in your head. One tip I've read is imagine a journey you take each day (like from school to home) and at key landmark points make a statue (in your imagination) that represents what you're trying to remember. The weirder the better. So now when you start talking you imagine the beginning of your journey. You have a giant cow giving birth to Christopher Columbus, because you're point is "The introduction of cattle to America", for example.
The general form of any written essay is to make each paragraph about one point. The first sentence states your point. The second and third support you're point, and the last one reinforces the overall point.
For example. The introduction of horse and cattle to Native American culture had a significant impact on their customs and way of life. (second sentence) Prior to Christopher Columbus introducing cattle and horses to America the extent of agriculture of the native tribes was limited to crops. (3rd sentence) They were also limited in the range of their nomadic movements and their ability to patrol and explore their surroundings. (4th sentence drawing a conclusion from the 2nd and 3rd sentences, and reinforcing the 4th) With the introduction of cattle and horses, the native tribes had to seek pasture land to graze their cattle, and were able to cover far greater distances with the use of horses.
So you imagine your cow giving birth (in your head), but imagine it standing surrounded by corn, and also on a platform too small for it. So when you start to talk, you see yourself at the beginning of your journey (just outside your front door) and you see the main points straight away. Cows. Christopher Columbus. Corn. Too small.
There's enough there to help you remember each point you want to make. You just need to make 10 more statues. Basic tips. Don't make them TOO complicated. After practice you can but if you make too many details you'll get panicky about forgetting your memory statues. Keep it sharp and basic.
If you find every thought goes out of your head, then just walk to the next statue in your mind.
Another good thing is to just make sure you know and understand what you're talking about. It's much easier to talk about something if you feel someone has asked you a question and you're trying to explain it because you do actually KNOW about it. Imagine it like someone asking you to explain a plot to a movie, or how to play a videogame.
Also as you're talking try to step out of yourself a bit and notice if you're talking too quickly, too quietly, or just rambling. Then relax and go back to talking.
I hate public speaking, but I did this method and always got A's for every speech I did. The funny thing is I was so nervous I barely remember what I said.
Also if you get nervous about public speaking remember this golden rule. I'm assuming everyone else in your class has to do this speech, and you've probably seen a few already. Did you care what the person said? Did you really listen? Did you notice if they were nervous or confident. If you're like me you probably find you didn't really care what they said. Don't get me wrong, I politely listen but didn't really care what they were saying. Now once you realise everyone listening to you probably feels the same way, it takes a lot of the pressure off.
Good luck.
