I built Susy, a Sass grid system that can generate any grid technique you like — but I haven't used it in years. I'll show you how various grid systems work, and how to avoid using them. For those few cases where a grid really is required, we'll talk about the best ways to roll your own, so you're not relying on a bloated library to make decisions for you. We'll also look at the new layout toys — from flexbox to CSS Grid — and how to get started with only a few lines of code.