This is the kind of thing we've presumably internalized as we work, but for me, at least, it's good to step back and realize that these are actually techniques and should be considered more consciously, too.

Great read. I really enjoy articles that use solid examples, rather than anecdotal evidence of solutions.

Anyone looking to read further into the design theories of affordance, signifiers etc. should check out the always classic 'Designing Everyday Things' by Donald Norman.