We cut our usage by over 30% last year making these easy changes:
1. Don't be on auto-flush
I'm a person who routinely glugs huge amounts of water, iced tea and coffee every day. Subsequently I am constantly using the bathroom! Our toilets are the low-water usage kind which I think now are code in L.A. But still....1t takes 1.5 gallons every time.
Obviously if you live in a house with one bathroom and 10 people it's harder than if you live with four people and 2 bathrooms but what we do is basically use our the bathroom in our bedroom and only flush it a couple of times a day. Guests always use the "flushed" bathroom anyhow. I'm sure we save 100 gallons a week doing that!
2. Keep these groovy IKEA watering cans in all the sinks!
http://www.ikea.com/us/en/catalog/products/20118230I love this design because it's low-slung and fits even in small bathroom sinks. The white one blends right in with white porcelain and doesn't set off my "clutter-itis." The handle doesn't go over the top and so, it doesn't get in your way. And it's only $2!
You would not believe how many times a day you fill this just washing your hands or rinsing out glasses, coffee mugs etc.
I keep a 5 gallon bucket in the shower-tubs of each bathroom and as it fills just throw it in there. Before showering, empty the bucket into the driest part of the garden.
3. Leave the bucket in the shower while showering
And the next morning you will have another full bucket to take outside.
4, Reclaim some of your laundry water.
At least with a top-loading washer, you can do this! At the end of the soak cycle before the water drains, dip a couple of watering cans in. As long as you use a bio-degradable soap and no bleach, your plants will not mind the soapy water at all.
Granted there are many variables that would make parts of this unworkable (for instance if your bathrooms were upstairs or far away from your garden) but for us it's been easy to fall into these habits and really besides conserving what is a very precious resource here -- who wants to pay more on their water bill than you have to?