One of the biggest procedures/mechanisms that has impacted me (beyond the BW transparency) is “play to see what happens” or “plan the scenario, not its outcome.” Seems rudimentary, but again, in a lot of trad games and groups, the cult of the GM is so strong that things can get screwy if you aren’t resolving situations as the GM planned or wanted. Dogs in the Vineyard was eye-opening to run. That game changed a lot for me.

Also, your differentiation between mechanic and mechanism is how I feel about comic vs. comedian in that, as far as I’m concerned, you read the former and listen to/watch the latter.