This paper is taken from the forthcoming book “What’s So Wrong with Patching Anyway?: A pragmatic guide to using aspects and e.” It addresses aspect-oriented programming (AOP), focusing not only on the academic side of the subject, but on the more pragmatic one as well, and provides real examples of AOP in action. It offers guidance for using AOP in ways that make code easier to write, easier to use, easier to reuse, and that can help programmers stay on schedule.