I live in a home with a slab foundation. This means it's really darned hard to access my greywater before it hits the septic tank. My washer is located in the dead middle of the house, making it impossible to run a pipe outside... the showers and baths drain directly into the floor... and only one of my sinks was located next to an exterior wall: the kitchen sink.
So I did what any reasonable man would do. I punched a hole in the wall, ran a piece of PVC from under the sink (after the P trap), put an elbow on it outside and ran it off into a bed of mulch by my banana trees.
I also added some papyrus or bulrushes of some sort, a few malanga plants, and a few more little banana trees.
I didn't want the water draining directly beside my foundation, so as you can see, I put in a 45 degree bend away from the wall. About 18" down that final piece of pipe, I started drilling lots of little drainage holes. The whole pipe was then laid into a little trench and covered with mulch.
The downside of this plan is that I can no longer use regular dishwasher powder without salting the bananas. So we're washing by hand a lot more and using as little detergent as possible. We'll see how the plants manage. If this is a FAIL, I can always reconnect the water to the septic. But that just seems like a horrible waste. I wish I could get off the septic tank altogether and just run all the house's water into the yard.
Perhaps one day I'll figure it out.