Write a draft of your speech in English. Touch on all of your key points. Try to keep the ideas and sentences simple. Do an outline first if that helps you to organize your ideas.
Write your speech in simple Japanese. Do not translate your English speech word for word, as this will likely make no sense. Instead, translate your ideas into basic Japanese. Use the polite tense, where sentences usually end in desu or masu. The casual form would be rude, and the humble form may sound strange.
Use a dictionary for difficult words and text to speech service to work on pronunciation (See Resources).
Practice your speech with a Japanese-speaking friend, who can fix your mistakes and address any issues with your pronunciation. If you do not know with whom you can practice, register for an account with an online language exchange service, such as My Language Exchange (http://www.mylanguageexchange.com/). This site allows users to practice their speaking skills online. Tell your partner that you would like to practice your speech and ask him/her for input. You may need to connect a USB microphone if your computer does not have a built-in one.
Edit and modify your speech as per the person's instructions. Try not to add any new information after this point, or you will need to check your speech again.
