Greywater is lightly used water and comprises 50-80% of residential waste water.
During the summer, keep a container near the sink. If you know you're going to rinse your hands or just rinse a glass out or wash produce, rather than dump it down the sink, dump it into a container. At the end of each night, use the water to water your plants.
Wouldn't you feel better that you're getting a second use out of it? You will save money and your plants will benefit from it. It's okay if it's a little soapy. It will keep the bugs away. Also, fix leaking faucets immediately and replace old fixtures with new ones. They are inexpensive, more efficient and will lower your usage. We replaced our sink faucet and shower head and our water bill went from $33 to $17 and we're just 2 people.
As an experiment, I cooked dinner and cleaned the kitchen afterwards and saved all the greywater. At the end of the evening, I already used 4-gallons of water. It really makes a difference when you look at it that way.