Here is a nice, quick, and simple way to enhance the definition on pictures. Intricate detailing work can be highlighted when processing using a quick adjustment using Aperture.
This works best if you are shooting RAW.
Under the “Adjustments” tab, find the “Enhance” section, and slide “Definition” as required.
It makes a subtle but noticeable difference, as you can see in the two images below (look for the depth in the detailing on the building);