Daniel Solis (@DanielSolis) on component-first design:
“Grab some dice or cards and just play with them, the old-fashioned way. Explore their physical properties, see what they can do on the table. How heavy are they? How do they fit together? What combinations are possible?”
http://danielsolisblog.blogspot.com/2014/05/3-simple-steps-of-component-first-design.html