Answer: To have a effective multimedia presentation, Write out exactly what you want to say, and include multimedia cues in your script. Practice it by yourself to make sure you can develop a smooth tempo, and then try it out on friends or colleagues. It helps to have a mixture of people familiar with your presentation subject and those who are not in your test audience, don't forget to add something that is aesthetically pleasing and consistent enough not to distract attention from the subject and the author, and significant enough to be an ideal addition to the words which are spoken.
hope this helped :)