Are you struggling with the “rule of thirds?” If you’re cropping in Aperture and you’re not sure where your subject should be placed relative to the rule of thirds, Apple has a trick up their sleeves in Aperture that just might help you.
Select the image you want to crop. Then select the Crop tool (C – shortcut). As you start to draw the crop area across the screen, simply press and hold the Command key. This will superimpose a grid over the photo that illustrates the rule of thirds, and helps you decide where to place your subject.