Flexbox Cheatsheets
Website layout has always been tricky business, and it only gets trickier with the proliferation of different screen sizes and orientations. Flexbox is a great way to make a website responsive to the multitude of target devices. Beau Carnes has an excellent cheatsheet on the Free Code Camp blog, complete with animated illustrations:
https://www.freecodecamp.org/news/flexbox-the-ultimate-css-flex-cheatsheet/
Chris Coyier's Flexbox guide has been my go-to resource for a while. He includes several handy examples for common layout situations: