Create an Oasis with Greywater

I know that a lot of the water we use in our house goes straight to the septic tank despite being fairly clean. The idea of reusing that mostly clean water for watering a garden or a lawn really appeals to me. I’ll have to see if I can find a copy of Cool Tools: Create an Oasis with Greywater via a library to see how difficult / costly it would be to implement this in a standard home. I’m not a big fan of lawns or gardens so I probably won’t bother if it’s too much of a pain, but I’m not a big fan of pouring usable water down the drain either.