Did you ever stop to ponder the ridiculousness of self-flushing toilets? Conventional toilets use two gallons of water every time they flush—think about how much is wasted when those automated versions malfunction. But you can do your part to conserve water at home by installing low-flush toilets whenever possible. And when you’re faced with an old school option that actually involves a handle or button, remember the hippie mantra popularized 50 years ago: If it’s yellow, it’s mellow; if it’s brown, flush it down.