Before you start developing a design, you need to understand exactly what needs to be done. A brief will help you figure this out.

A brief document containing important details of the project helps to form a unified vision with the customer and avoid edits.

This document resembles a questionnaire that can be sent to the customer to fill out (but it is better if you fill it out yourself, clarifying the points with the customer). The brief will help to create a unified vision with the customer and avoid an excessive number of edits in the future. 

• Presentation type -Presentations do not necessarily accompany the report, they can be forwarded to individual people to convey some idea. For example, it can be a report on the work done for the head of the company. How exactly the presentation will be used depends on its content and appearance. Therefore, it is important to ask such a question to the customer.
• Audience - To whom the speaker will speak or to whom to send the presentation.
• The purpose of the presentation and the useful action -It is better to discuss these issues with the customer again so that you do not have disagreements. (more on this here)
• Materials from the customer - there may be texts, important indicators, graphs, diagrams, product photos, illustrations, videos. Sometimes companies have a corporate template so that all presentations are in the same style — it can also be requested from the customer.
• Company information - If you make presentations on a freelance basis, it is useful to clarify what the company does, who its customers are and what product it produces