I honestly can't imagine ever going back to purchasing laundry soap again. This soap is pretty (which I know isn't important in the long run, but I don't like doing laundry and if I have something pretty to look at it definitely helps), smells nice, cleans well, and every time I use it, it's just a nice little treat for me--as much of a treat as you can get from washing dirty clothes and towels anyway.
You want the recipe? Of course you do. Here it is:
(Most of this can be found in the detergent aisle, with the exception of the Baking Soda and the Zote Soap)
1 (4 lb 12 oz) Box of Borax (sometimes I can only find a 4 lb 1 oz box, so I use that)
1 (3 lb 7 oz) Box of Super Washing Soda (Arm & Hammer)
1 (3 lb) Container of OxyClean
2 (14.1 oz) Bars of Zote Soap (I found this at our local Latino market. If you can't find it, you can use an equal amount of Fels Naptha, but those bars are smaller, so be sure you get 28 ounces, not just two bars)
1 (4 lb) Boxes of Baking Soda (Arm & Hammer)
1 (55 ox) Bottle of Purex Crystals Fabric Softener (optional--but it smells nice, makes the detergent look pretty, and softens the fabric(again, sometimes I can't find this size, so I use a smaller (generally 39 oz) size)
Grate the bar soap--I used my food processor, and it worked great. If you want smaller bits of soap, you can do it by hand, using the smaller holes on the grater.
Next, get a five-gallon bucket, and start mixing everything together. Unless you have arms of steel (I don't), I recommend a layering approach to this--like dump about 1/4th or 1/3 of each ingredient into the bucket, then stir them all together (I use a wooden spoon). Then repeat two or three more times. I like to use the bucket that I'm going to store the soap in. Saves time and effort.
Now you're done! I like to store my soap in a large bucket in our shed, and then fill the OxyClean Container (which I covered with paper and re-labeled to avoid confusion) with a manageable amount with soap to keep in the laundry room.
To use the soap, just put in 1-2 Tablespoons (I add a heaping tablespoon) in with each load of laundry. You'll think you need more, but really you don't. Also, you will notice that your water doesn't have the suds that you're used to. That's okay, your clothes will still get clean. After this experience, I have a sneaking suspicion that companies put sudsing agents in their detergent more so that you will think it's doing a better job rather than because it is actually needed.
Also, as long as we're talking laundry and saving money, I use golf-ball size spheres of wadded up aluminum foil instead of a dryer sheet to break up static cling. It works pretty well. My dream is to have one great big huge ball, but for some reason I can't bring myself to cut up a piece of foil long enough, so right now I have four or so different balls bouncing around with each load I do, and it works almost as well as a dryer sheet, so I'm sticking with it.