Original Oratory is a process. It begins with selecting a topic, then research, followed by writing a speech, then interpretation and practice, and ending with performance. Topic selection is arguably the most important step as it starts the Original Oratory chain of events. Thus, when selecting a topic you need to be mindful of a few considerations.
Choose a strong topic. Your Original Oratory topic is what your thesis statement (sentence that explains what your speech is about and your stance/opinion) is derived from. That thesis is what will motivate and influence all research done for the speech. The thesis is also what your writing will develop from. In short, a weak topic selection can lead to a weak thesis which can doom an Original Oratory into mediocrity.
Risk and originality. Sticking to a topic that has been done over and over again is grating to those who have to listen to those ideas year in and year out. That is, of course, if you are not adding a personal spin to the thesis. Original Oratory is...well...original. Making a topic personal and adding yourself can turn even the most done topic into something fresh; do not imitate another OO! New research to cite helps too! If you wish to avoid the unoriginal factor then try to think of a new, risky topic. Boundaries exist, but choosing a controversial/taboo topic to write an OO about can instantly draw in your audience.
Holds universality. Universality is just a fancy way to say that the topic can captivate the interest of a majority of the audience. You should never select a topic to humor audiences, but try to chose a subject that others can find interesting. Holding an audience captive and raising their curiosity in an issue are goals any Oratorical speaker should work towards.
Can be researched. Original Oratory is the Forensics world's version of the research paper. It is difficult to cite anything when sources are near non-existence. This can either come from the selected topic not having much resources written on the topic OR because the information is not accessible. Either way, this leaves you in a a limited position of what you can learn and cite regarding the issue.
Be concise. Select a topic that can be turned into a concise thesis. It is hard to write a paper when the thesis is so broad that it seems as if the topic changes mid-research. Be narrow. The larger a thesis/topic is, the easier it is for the paper to enter inflation as you try to touch upon every idea or tangent you can find. Find the main idea of a subject and write about that.
Love it. If you do not love your topic then that will be reflected in your Original Oratory. Your analysis will be rushed, your delivery flat, and your research thin. Love what you do. That too reflects into your performance.
These are just a few of the basic queries to ponder as you decide upon an Original Oratory topic. In the end, the decision is yours. Do what feels best for you and your piece and prosperity should ensue.