These strategies are based on studies of visual perception conducted by Gestalt psychologists at the turn of the century. Your eyes will automatically perceive elements located near to each other as being related to one another. So, items that are conceptually related should be grouped together. Likewise, spread out elements that aren't conceptually linked. Think about where the viewer's eye looks first and how it scans around the elements on the slide.
Contrast Related to proximity is the idea of contrast .
Make elements that aren't similar very different from one another. This stimulates visual interest, and if it isn't interesting, it won't be read. Alignment Expanding on the idea of proximity, don't place elements randomly. They should all be aligned or connected with some other element. This helps direct the viewer's gaze by providing a visual organizational structure for the screen elements.