A Practical Guide to Flexbox: Don’t Forget about flex-shrink by Noah Blon on CodePen
A deceptively simple but powerful use of flexbox.
Link archive: June 3rd, 2015
Interface Experience Maps, From the Notebook of Aaron Gustafson
This sounds like it could be a very useful tool to introduce early in projects to get a shared understanding of progressive enhancement.
Dev.Opera — Making websites that work well on Opera Mini
Using Progressive Enhancement makes your site better for all users and enables the 275 million users of Opera Mini worldwide.