Getting Development Group To Adopt New Practices?

maiden_taiwan asks: "At my software company, we occasionally need all engineers to adopt a new standard or 'best practice.' Some are small, like the use of Camel Case for function names, while others have tangible business value, such as 'every check-in must be accompanied by a unit test.' As you might guess, some new practices get ignored, not because people are evil or lazy, but because they're simply too busy to pay attention and change their work habits. So we are seeking creative ways to announce, roll out, and enforce a standard for 100+ engineers so they will actually follow it." What ways have you used to convince your developers and engineers to adopt a new set of practices that may or may not get in the way of their daily work habits? We already know to automate compliance when possible (e.g., the revision control system could reject check-ins without unit tests), and simple platitudes like 'tie compliance to their year-end bonuses' aren't helpful by themselves, as someone will still need to check compliance. The engineers here are smart people, so we want to spend less time on enforcement (having architects read the code and flag any non-standard practices) and more on evangelization (getting engineers to see the benefits of the standards and -want- to follow them). I'd welcome any advice on formal processes or just plain fun ways to get people's attention."