How do you go about designing your personal projects? Do you hack them straight out or sit down and design them first (pencil and paper/UML)?
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.
The pencil and paper thing in my case works as a way to organize my thoughts and define what I'm actually going to do, rather than a formal design process. Usually I have an A4 sheet (or rather several) scribbled with ideas and sketches regarding a single project.
Any design would be totally just in my head. I'd only sketch something on paper if it's a GUI.
The design that's in my head is basically a short list of what it should do and what it should not do.