The document discusses key principles of design including: using white/negative space to draw attention and provide breathing room; employing contrast through varying sizes, colors and shapes; creating symmetrical or radial balance through centering or arranging elements; implementing asymmetrical alignment with odd numbers of off-center elements; aiding navigation through repetition and consistency; dividing the page into thirds using the rule of thirds; grouping related elements with proximity and unity; locating the optical center slightly above and to the right of the mathematical center; following the z-pattern visual path; and using white space between all design elements.