The purpose of a conference presentation is to tell people what your work is about, why it is important, how you went about it and what you discovered that we did not already know.
Conferences run to a tight schedule, typically allowing only ten minutes for each presentation. Find out in advance how much time you will be allotted for your presentation. In such a short period, it is impractical to put over more than three real points. Remember that the audience have your paper and that they will be able to read it later. Your aim in your presentation is simply to get them sufficiently interested in your work to generate discussion during the discussion period and to get them to want to read more, later. The golden rule is to simplify what you are trying to say and then exaggerate the points in order to generate interest. Forget the detail. Make sure that your talk progresses through a series of logical steps, so that you finish with a clear conclusion. The worst thing is to finish by saying "I was going to say something else but I have run out of time"! If you are not sure how much material will fill a ten minute presentation, practice it first with friends or colleagues.
Repetition is essential in a spoken presentation. People cough, sneeze, nod off or whatever; they miss things. The significant points must be introduced before they are made and reiterated afterwards. Towards the end of the talk, summarize the main points. People will remember most the first things and the last things that you say. Therefore, speak at your loudest and clearest when you first open your mouth. Do not fumble through notes or with trying to get your PowerPoint slides to display; get these ready beforehand. If possible, try out the room and the visual aids in a break before your talk. Also, if you are not the first speaker, you can practice talking to the particular audience by making comments or asking questions on other presentations.
If you are using slides or presentation software, do not use too many. Two or three are more than enough to fill ten minutes. Do not put lots of small text on them that cannot be read. If you are just making a summary of the main points of your paper, you should not be drawing attention to the fine detail of the data.
If you are using power-point, please avoid excessive animation and flashy colours. They serve only to distract the audience from the point of your work. (It is useful to remember that power-point was developed for business presentations, not for scientific presentations, which are very different.) Better still, do not use slides if they contain only your own notes in bullet point format. There is no need to show your notes to the audience. Doing so will only draw attention to the things you have to miss out when you run out of time. Moreover, it will be difficult to adapt your sequence and flow to suit the way that the audience appears to be reacting to your talk. Use the slides only for graphical portrayal of things that are not easy to express in words. When you are ready to start, and your power-point file is open, remember that typing the function key F5 will start the slide show; this is much easier than trying to find and click on the little icon to start the slide show, which is in a different position in different versions of power-point. Practice this on your own computer, before you get up to speak. Get used to operating power-point in slide-show mode. Some people only use it in editing mode until the day they stand up to make their presentation!
With any form of visual aid, switch it off once you have finished referring to it. (In powerpoint, simply pressing the letter B during the presentation will turn the display all black; press any other key to bring it back.) Avoid passages of text on a screen, unless you are going to keep quiet for a few minutes while people read it. Also, never stand in front of the screen. There is no point at all in putting things on the screen and then obscuring them with your body. Stand next to the screen to avoid this problem.
Finally, be yourself; do not try to stop moving about the stage or using gestures, if that feels natural, and do not force behaviours that do not suit you. You only have time to make a few points and to raise the general level of audience interest in your work. The main aim of the conference is not the presentations, but interaction with your peers.