It really depends on the scope of the project. Simple projects I just hack through, which acts like a design process. In 2004 I built a personal delicious clon

It really depends on the scope of the project. Simple projects I just hack through, which acts like a design process. In 2004 I built a personal delicious clone, which I pretty much hacked together in a week. Overtime I added more and more features. Now, I'm contemplating rewriting it in a framework. It has grown past a weekend hack so now I'm mapping it out. It's best to know how you work. For me its better to have a working prototype that I can tinker with, even if I know I'll rebuild it eventually.