An excellent slide deck describing experiences, common pitfalls and good practices of developing responsive websites: Pragmatic Responsive Design on Slideshare.
I was quite encouraged to see a number of my own practices being mentioned such as designing in the browser and augmenting the initial mobile stylesheet with additional rules only.
I also liked the terminology of major and minor breakpoints, for layout changes, which I hadn’t heard before. There are also good points on feature detection and adaptation which I plan to look into further as I’ve tended to design for smartphones and tablets rather than less capable devices.