One-day challenge

Try going one complete day spending absolutely no money - no charges to a card - no online orders - etc.  It's a bit harder than you think.  You may find yourself reaching into your pocket for change for a vending machine...  Nothing creates a clearer picture of how consumer-oriented we are than to "fast" from consumerism for an entire day.  Stock up ahead - fill the tank with gas - be sure there's food in the fridge, etc.  When you succeed with one day - try a week.  It's truly a consciousness-raising activity :)