Yes, existing files may be sufficient (assuming they are not drafts). Although Microsoft Word or Powerpoint are considered professional Office programs, they are not professional prepress applications. Adobe InDesign, Illustrator, Photoshop, and QuarkXPress software can, in the right hands, produce the best results. With Complete Service, data from Office programs is reformatted with professional prepress software before output.
Use Quality Content
The first step, of course is to develop good content. It should enlighten viewers, perhaps supporting a bold claim that can be adopted to advertise a new product. It may establish the validity of a supposition, leading to further research grants. Subject matter should be thorough without obfuscating main point in a sea of technical vocabulary unfamiliar to the audience.