Inside my house I leave buckets under the downspouts. Large ones in the tubs, watering cans and smaller buckets in the sinks.
To harvest rainwater I have 3 rain barrels set below my downspouts. Actually they are heavy duty trash cans that I convert to potting soil containers in the summer. The rain gutters are cut at the correct height for the barrels, and I surround these barrels with 5 gallon buckets waiting to handle the overflow.
Hanging plants conveniently drain on to potted plants placed underneath.
Having a lawn can be pretty, but the water use can be hard to justify. Warm weather grasses (like St. Augustine) can tolerate more heat and less water. I try and get by with one day of watering a week through all but the hottest of summer months. By placing raised garden beds on my front lawn, I grow 3 seasons of crops a year. The beds cut down on the lawn mowing and watering, and I am rewarded with local organic produce.
Now when I water, much of it is used on fruit trees and edible plants. Lawn cutting and edging also takes less time. By saving water where I can (lawn and ornamentals) and using it where I need it most (potted plants and edibles) I keep my water bill below the average for our area. As a gardener and environmentalist I call that a job well done.