This is also a good moment to remind people that you don't need Bootstrap and the like as much as you used to. Grids were 90% or the reason people started using these frameworks, and CSS (already with flexbox I'd argue, but definitely with grids) has caught up and is now easier to use and more flexible than any framework was.
It's also time to reconsider the atrocity that is class="col_xs_12". I've never undestood why people would lynch anyone using style="..." but happily littered their code with those grid classes. With the invention of sass at the latest, actual semantic class names should have once again become the only acceptable best practice. With html5, there's also a range of semantic tags[0], and using them improves both code readability, as well as allowing all sorts of new ideas in clients (not just browsers, but also text-to-speech and other accessabiity tools, or spiders, or brosers on new device classes)
o: <article> <aside> <details> <figcaption> <figure> <footer> <header> <main> <mark> <nav> <section> <summary> <time>