I've found the best way is to build things over and over again. That may reflect a certain learning style but actually manipulating styles and layouts really helps hammer home the practical aspects of how it works.
I also approach writing CSS with the goal of writing as little as possible. Not because I don't like it - I tend to think it gets an unfairly bad rap - but because it teaches you how to more effectively style layouts without layering too many declarations.
I also approach writing CSS with the goal of writing as little as possible. Not because I don't like it - I tend to think it gets an unfairly bad rap - but because it teaches you how to more effectively style layouts without layering too many declarations.