During the design phase of my programs, I often break down the problem first, and once I have it broken down then I can easily start to recognize patterns inherent within the design. At that point, I can begin to apply well-known design patterns so that when it comes time to communicate or implement the design, I have a common language I can use for communication, and hopefully I can re-use some generic objects that were previously implemented during the implementation of a similar pattern.
Often times, when design patterns are applied incorrectly, it's because the process happens in reverse. Programmer Joe (my apologies to those of you named Joe) reads a book on Design Patterns, and says "Ok, I understand Design Pattern X, now how can I apply it to my application?" This is wrong.
Design patterns can be a mighty weapon, but like anything else, they should be used appropriately, and the programmer should always be prepared to incorporate some original thought into his design, as well.
