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. When to use floats, CSS Grid, flexbox, custom properties, and other techniques. How to make grid-math simple, and lose the grid-system. How to make existing grid-systems work for you, when you’re stuck with them.