Well the very first thing one should do is present themselves to the audience. Then I like to capture the audiences attention by starting off with a statement, quote, fact, something fun, etc. I then somehow tie it to the topic of the speech and start introducing my ideas while supporting it with evidence. I like to end my speech with a bang so lastly I mostly always use pathos by ending with a call to action or something that makes the audience left to wonder about what they should do.
