I've been making/using this for years. I'm not a total convert because I am known to buy a bottle of Tide (or All, etc) if it is on sale and I have a coupon....
Homemade Laundry Detergent
1 box Borax (the 4 pound, some odd ounce box)
1 large box baking soda (get the cheap stuff- I think it is like a 2.5 pound box)
2 bars of Zote soap (look in Hispanic stores or the Hispanic section of large retailers)
In a large container add the borax and baking soda. Stir together, you may have to break up the lumps of borax with your hands.
Grind/grate/shred the soap with a cheese grater. I use a rotary one from pampered chef. Add to shredded soap to the borax mixture and stir well.
To use: use 1/3 cup of the mixture and add about 1.5 cups water to the mixture. Microwave for approximately 1 minute to melt the Zote soap. Add to laundry machine.
I use a front loader and my clothes are not too dirty when they are washed. You will still need to pretreat stains and add what additives (ie bleach) that you would normally use. I use the same glass measuring cup for the microwaving step over and over again as it saves having to wash the cup. you may need to adjust the amount of soap based on your machine and the dirtiness of your clothes.
My ex really liked this laundry detergent because it is unscented. I used this on my kids baby clothes with no problems or skin reactions.