"TANSTAAFL! - There Ain't No Such Thing As A Free Lunch."
I liked this acronym so much I had to post it. I ran across it in one of a group of amazing articles that depict working in test driven development: Test Driven Development - Craftsman series.These are actually all the same long article divided into smaller pieces. Be sure to read it from the start (bottom of the page) to get the full picture. Along the way they deal with the notions of test-first,test as documentations, testing multi threaded, mock objects and lots more.
Another nice (even though weird at times) idea is “Code Kata“s -
A kata is an exercise in karate where you repeat a form many, many times, making little improvements in each. The intent behind code kata is similar. Each is a short exercise (perhaps 30 minutes to an hour long). Some involve programming, and can be coded in many different ways. Some are open ended, and involve thinking about the issues behind programming. These are unlikely to have a single correct answer. I add a new kata every week or so. Invest some time in your craft and try them.
I found it interesting, although I'm not sure how much practice I'll actually do of these, but it's really cool to find stuff you never even thought about - Code Kata
Both of these links were picked up in the win-tech_off_topic mailing list during a discussion of how to survive ever changing project feature requests.