I am re-reading Michael Feathers' post: ... You think your design is good? Pick a class, any class, and try to instantiate it in a test harness. I used to think that my earlier designs were good until I started to apply that test. We can talk about coupling and encapsulation and all those nice pretty things, but put your money where your mouth is. Can you make this class work outside the application? Can you get it to the point where you can tinker with it, in real time, build it alone in less than a second, and add tests to find out what it really does in certain situations. Not what you think might happen, not what you hope might happen, but what it really does? ...
Well said, I should read this every morning...
http://www.artima.com/weblogs/viewpost.jsp?thread=42486