Use the grid and the rulers when you position your shapes on the page.
If a diagram contains many shapes, it has the potential to get cluttered. Flowcharts, org charts, and Web site diagrams are examples that come to mind. One way to fight the clutter is to arrange shapes by using the grid and the rulers.
When you position shapes on the page — or when you first add shapes to the page — use the grid lines to keep them straight. And keep an eye on the grid to make sure that your shapes are evenly spaced.
The rulers are also invaluable. Use them to see the exact distance between shapes or to know just how big a certain shape is. These numbers are especially important if you are creating a detailed office layout or building plan that will control physical measurements.
By default, shapes snap to the grid lines and the measurement lines on the rulers. This behavior makes it much easier to position shapes. You don't have to do fussy hand work to get a shape in the right place. It puts itself where you want it, and it stays there unless you move it.