A Concrete Example
Uncommon11.1%GrindOptionalAnywhere
Build 5000 Foundations.
Strangely, this might be one of the longer grinds in the game.
Make a habit of laying foundation for any piece of base you build, including resource outposts and such.
Its worth always carrying a good stock of Iron Plates and Concrete in your personal inventory so you can just lay out more foundation whenever its useful.