18F Methods
Design isn’t all about “making it look pretty”. Design is about making something usable and easy to look at. This site is created by the US government in order to share a collection of tools that describe how their teams put human-centered design into practice. The main focus of human-centered design is incorporating feedback from the actual people you are designing for, not just the people who are having you design something.

Degreeless.design - Everything I Learned in Design School
The author of this site went to school for design and put most of it online. As they said: “This is (almost) everything I learned in design school in one website.”

Cedar Design System
Did you know that REI, the outdoors store, has open source projects? I didn’t. Cedar is their collection of UI elements built with Vue.