If anyone needs a handy cheat sheet to guide you with flexbox, here we go. I found this very useful when doing the responsive web design course with Kevin Powell.
#Your cheat sheet for Flexbox
vast arch
agile cloud
Nice. My go-to flexbox resource is usually this one: https://css-tricks.com/snippets/css/a-guide-to-flexbox/
short folio
Even for grid, css-tricks's cheatsheet is the best and quick to access.