The thoughtful alignment and distribution of icons can significantly improve the visual appeal of a drawing with a minimal amount of effort. Take this excerpt for instance:
It's easy enough to follow, of course, but it lacks a professional feel. How can we improve it? To begin, we should realize that related objects should be aligned within a group. This conveys a subtle but powerful sense of relation without requiring any additional shapes or text. The workstation icons should be aligned vertically as the devices they represent exist in parallel with one another.
Using Visio, we can align the three icons by selecting them, then navigating to Shape -> Align Shapes and clicking the button for vertical alignment by object center. (Actually, since the icons we're aligning are all the same size, all three buttons will have the same effect. I just seem to use center alignment most frequently.)
Once our host icons have been neatly aligned, we can evenly distribute them to further enforce the impression of mutual relation. With the icons still selected, navigate to Shape -> Distribute Shapes and select the option for horizontal distribution by object center.
You'll notice that the middle host is centered on the midpoint between the two outer hosts; the vertical axis of this host now serves as an ideal horizontal center for the rest of the drawing. We can align the router and switch above the center host, but the icons must be selected in a particular order for this to work.
First, select only the center host. Second, additionally select (ctrl-click) the switch and router. By selecting the host first, we ensure it is used as the reference point by which the other icons will be aligned. Navigate to Shape -> Align Shapes again, this time selecting horizontal alignment by center.
Vertical distribution of the router, switch, and center host isn't necessary, for two reasons. Primarily, they aren't related, and thus no relationship needs to be conveyed. The alignment of these objects is simply an aesthetic touch. Second, vertical distribution of objects isn't as important because of the way we humans perceive symmetry; we naturally lend much more weight to horizontal symmetry than we do to vertical. However, vertical distribution is still recommended where appropriate (for example, if our hosts were stacked on top of each other rather than laid out side by side).
Our finished drawing is much more appealing than the original, despite conveying exactly the same information.