There are tons of tutorials to show you how to start testing your website with Behat. But how do you write effective tests? How do you know what sections and flows in your application need to be tested? In this talk, I'll share my experience over the last two years of diving into using tests for both client projects and our own website. We'll look at what makes a useful Gherkin test, using Mink to test your site, and how to identify where to start and what to test.