The document provides guidance on writing effective presentations by discussing the structure and components of introductions and conclusions. It notes that introductions and conclusions should be concise, occupy less than 20% of speaking time, and leave lasting impressions. Various types of introductions are described, including identifying with the audience, stating the purpose or importance of the topic, surprising with a statistic, using an anecdote, posing a rhetorical question, or employing humor. Common functions of introductions are to get attention, introduce the topic, provide motivation, and establish credibility. Examples of different introduction structures are also provided. The document then discusses types of conclusions such as summaries, quotations, personal references, or calls to action. Functions of conclusions include