In this talk, I will take a look at all the features Sass and Compass put at your disposal, showing you how they can be used in real-world situations with a case study from the new Persil.co.uk website. From making complex responsive front end builds more manageable, working with custom IE style sheets, all the way through to improving the consistency amongst a team of developers. All of this formed part of the work that went into the new Persil website. In the last few years we’ve become quite accustomed to increasing our productivity with preprocessors like Sass or LESS. But how many of us take it much further than using a few variables, nesting our selectors, and using partials. Sass brings much more functionality to the table, including loops, conditionals, functions, and mixins. Now bring Compass into the mix and you have an even more powerful combination with added functions and built-in mixins. I'll show you how you can start cleaning up your own Sass with these advanced techniques that we've been using in the Persil project.