Instal a water butt or any huge pot or container to collect rainwater and use it for watering the garden and washing the car! You can also leave gardening trigs and buckets in the open especially during rainy days and collect all the water for your indoor plants and outside ones.
For a cheaper butt, think about a re-used juice storage tank. Old orange juice containers, with a capacity of 1,500 litres would be ideal. In fact any large tubs, buckets, vessels, biscuit tins etc. that you have not been using, can fill up rainwater for you!
pics and text: daksha