A year and a half ago I wrote a post called My Gameplan for Starting a New Project from Scratch that just detailed my thoughts on starting up a new project. I was asked via email last week if I had any changes to that post. Yes, absolutely:
Follow it Through!
Don't jump into the work too early without a good story backlog definition, an understanding of the goals of the system, and some inkling of the expectations of the client (which are undoubtedly going to turn out to be ridiculously unrealistic).
All processes, even XP and Scrum, have some sort of fuzzy project conception phase. The activities that you perform in that phase are crucial to the success of the project by preparing the field, but easy to neglect because there isn't much pressure upfront and the feedback loop that says "you're wrong!" hasn't started yet. On the other hand, I think you need to work with a sense of purpose early in the project to get through that initial phase and get started. In My Gameplan post I talked about the importance of getting momentum early on in the project. That's largely based on my experiences in a large organization that let the early phases drag on way too long. After doing three projects and starting a fourth since that post, I'd still err a little bit on the side of starting the coding in earnest too early rather than too late.
I did have some issues with coding outrunning the build, test, and deployment infrastructure. Take care of that stuff as early as possible. Especially early on the project, if you see chances to add some automation to reduce friction, do it right then. Investments early on pay off more in the lifecycle of a project.