As in the case of written presentations, do not rehash an old paper or speech. There are two exceptions. The second exception is that, if you have faculty authorization , you may substantially alter an old paper for an oral presentation. There are several ways to make oral presentations.
Notes are usually preferable, but, as always, rehearsal is essential.
A third choice is to read the paper, but you should be so familiar with the text that you can look at both your audience and your audiovisual aids. A fourth way is to memorize your paper, but you better have notes or text handy in case you forget it. Audiovisual aids usually substantially add to a speech. Handouts are also possible, but passing maps, pictures, and even handouts to the audience may be disruptive. You can make slides or overheads of most of these items, or scan them for a power point presentation.