Addicted to Every Possibility by Nathan Beck
Source: nathanbeck.eu
How would your design choices differ if you refused to display more than two user actions within the same view at the same time? How would you group and differentiate content if you disallowed the use of borders and shadows?
Far from being exercises in austerity, these limitations invite resourcefulness. They force a deeper reckoning with the fundamentals of structure, rhythm, and intention. They encourage inventiveness over rote repetition of existing patterns and standard practices.