Making your own laundry soap is quick and easy but the best part is that it's very very cheap. You can easily make 3 gallons of soap for about $3 and have virtually no waste whatsoever. Here's the info:
Make Your Own Laundry Soap!
1 bar soap
1 cup Washing Soda (not baking soda!)
1 five gallon bucket with a lid
3 gallons of water
Grate the bar of soap into a sauce pan. Heat up some water in a kettle and cover the soap with boiling water. Leave overnight to melt. If there are still chunks of soap in the morning add more boiling water until all chunks of soap are gone. Pour melted soap mixture into the bucket. Add enough hot tap water to make 3 gallons of liquid and then add the washing soda. Stir well and let sit overnight. Use from ½ cup to 1 cup of detergent per load of laundry at a total cost of approximately 3 cents per load!
You can often find a bucket for free at any industrial kitchen or grocery store where they make things from scratch or a place that sells honey in bulk. You can find washing soda at the Ballard Fred Meyer (so far the only place I've found it).