I had the opportunity to read Practices of an Agile Developer: Working in the Real World. The book has 45 tip to help developers become agile. And, it's clear that Venkat and Andy know the problems of becoming an agile developer, because along with each tip, there's a devil-thought to show people what happens in the real world. There are also angel-thoughts to show people why this tip works.
My favorite tip, and something I've been saying in my assessment reports for the last 10 years is “Architects Must Write Code.” (p. 155 in this book.) Venkat and Andy say this about ineffective architects:
They typically come in during the beginning of a project, draw all kinds of diagrams, and leave before any serious implementation takes place. There are many “Powerpoint architects” out there, and they aren't effective because of lack of feedback.
I've been a part of projects for 30 years. I've been assessing projects for 10 years. And every time I've seen an architect who doesn't participate in the code-writing part of the project, I've seen an architecture that doesn't do what it's supposed to do, never mind extend to inevitable changes in requirements that occur during the project.
Architects need feedback about their architecture. The only way to get feedback is to write the code, integrate it, and see what happens.