Conserve water. Turn off the faucet when brushing your teeth, and limit showers to five minutes. Install low-flow shower heads and water-saving toilets. "When Carolina's environmental science class learned to read meters and monitor their families' water usage, they discovered that our family was using one-tenth the amount of water that the other families were," says Lynne. "That really drove the lesson home."
Compost. Lynne and Eduardo use a method called bokashi, which involves throwing kitchen scraps in a plastic bucket along with a blend of wheat bran and aerobic and anaerobic microorganisms. It produces fertilizer in as little as 10 to 30 days—traditional composting takes much more time. And because microbes ferment the waste rather than decompose it, there's no smell. Carolina, Morgan, and Savannah help tend the mix and bury it in the soil near plants and trees. (Bokashi kits are available at gaiam.com.)
Buy clothes secondhand. Since they're sold twice, used clothes benefit the economy twice—without requiring additional resources. And you don't have to sacrifice style: Carolina, for example, loves to shop at Buffalo Exchange in Tucson, which sells recycled fashions geared to teens and college students.