1. Verify that your home is leak-free!
2. Avoid flushing the toilet unnecessarily.
Dispose tissues and other such waste in the trash can rather than the toilet.
3. Take shorter showers. Replace your showerhead with an ultra-low-flow showerhead.
4. Don't let water run while brushing your teeth, shaving or washing your face.
5. When washing dishes by hand, fill one sink or basin with soapy water.
Rinse in another basin filled with hot, clear water.
6. Do not use running water to thaw meat or other frozen foods.
Defrost food overnight in the refrigerator or by using the defrost setting on your microwave.
7. Water your plants during the early morning hours or at night when temperatures
and wind speeds are the lowest. This reduces losses from evaporation.
8. Fill a saucepan of water for washing vegetables rather than leaving the tap running.
9. Use a bucket of water and sponge for washing the car rather than a hose.
10. Once it has cooled down, use left-over water from cooking to water plants around the home and garden.
Source : http://www.ecoutlet.co.uk/blog/top-10-water-saving-tips-for-summer/