Two weeks ago, a designer sent in an app landing-page mockup with slanted buttons. I attempted to do this the most natural way, i.e. using CSS transforms via skew. I skewed the button selector and it worked beautifully, except that it skewed the text as well.

If you’re using CSS3 properties for graceful degradation, it’s probably fine to drop vendor-prefix support for certain properties. It’s best to educate clients about future maintenance woes and why it’s absolutely fine if Firefox 3.6 users will see square corners and no shadows, as long as you’re not breaking the site's layout.