Most professional presentations include an opening, key content, then a closing. The opening and closing tend to be shorter, with more emphasis being spent on the key content (body) of a presentation.
When you’re designing and developing your presentation you should begin with, and focus on, your key content. You should spend your time deciding on what to include, how to organize it, and how to structure it. Once that’s determined, crafting your opening and closing will be much easier.
Many presenters who attempt to begin designing their presentation with their opening end up altering their key content to fit their opening, as opposed to the other way around. Avoid frustration and misfiring in your next presentation and begin by focusing on your key content. Choose your content thoughtfully, organize it logically, then consider how to introduce it.