Speakers often forget that their speech will be seen and heard NOT read. They spend hours crafting the perfect words which is great if they were working on an essay. As a speaker, it is critical to know how you look and sound, and the earlier in the process you learn this, the better. As soon as you have a basic, rough speech ready, take out your smartphone, set it up on a ledge/shelf and record yourself. Watch the video, and I guarantee you will quickly pick up any problem areas. Keep practicing and recording until you are ready to present.