While their content and meaning may be quite clear to you after having created them and looked at them for the past x years, the same will not be true of most people in your audience. Work hard on your presentation and do not leave it to the last minute. Editing, practising, and timing your presentation are essential. Prepare all aids carefully and rehearse with these aids. Get into main subject quickly.
Strong conclusions are always very important.
Your conclusions are your take home message and may be the only thing that the audience remembers. Treat humour very cautiously. Stage presence is important. There are many small things that you can do about your stage presence that will improve your presentation. It is important that you know your way around the room in which you will actually be giving your presentation.