Turn off the shower tap while soaping up. By cutting your shower short by one minute, you can save an impressive 1,500 litres of water annually. Showering together is, of course, also a fun way to use less water.
Another tip: put two different bins in your bathroom, so you can already separate waste. Choose reusable packaging where possible.
Run your washing machine on the eco setting or a lower temperature; this, too, will save energy. Dry your washing on a clothes horse instead of throwing everything in the dryer.