One way I save a few pennies for our large family is by making my own laundry soap. A friend gave me the recipe and showed me how. It's kind of hard to figure out just how much it costs, but I believe it's less than $2 for about 2 gallons of laundry soap. Some ingredients take some looking for, and the price can vary drastically from store to store.
There are three basic ingredients in my recipe: Arm & Hammer Washing Soda, Borax, and Fels Naptha. It's important to use washing soda, not baking soda. (You can chemically change baking soda to washing soda by baking it!!) I've had better luck finding this near Amish communities. I've paid as much as $5 a box, and as little as $2.77 a box. It comes in 55 oz. boxes, and you only use 1 C. per recipe. Borax is easy to find in just about any grocery store or Walmart. Fels Naptha is trickier. I've searched and searched in stores I knew carried it. Sometimes it's with laundry products, but sometimes it's with bar soaps (it's in a bar). I've seen it for as much as $1.69 a bar, and just recently I found it at our Walmart for only 97¢ a bar.
Here is the recipe I use. If you Google Homemade Laundry Soap, you can find many, many recipes. Most are variations of this.
1/2 bar Fels Naptha, grated
1 C. Borax
1 C. Washing Soda
Optional water-soluble fragrance
2 gallon covered bucket
Put grated Fels Naptha in a stock pan with 6 C. water. Cook until soap melts; stir occasionally, about 8 minutes. Add Borax and Washing Soda; stir until dissolved. Remove from heat. Pour 4 C. hot tap water into the bucket. Add soap mixture and stir. Add an additional one gallon plus 6 C. water and stir. At this time you can add fragrance, if you prefer.
The recipe says to let sit 24 hours, stir and use (about 1/2 cup per load). I don't always let it sit that long, and there's no problem. Sometimes it has a thick gel consistency. Sometimes it's gel on the top, but watery on the bottom (I stir it up before each use to get some of each). I don't know why it varies.
I think it cleans as well as anything. You can use the Fels Naptha bar as a pre-treater, too. I miss the strong fragrance of store-bought laundry soap. I haven't found a fragrance to add that matches it. If you don't mind the lack of fragrance, it's no problem. The soap smells very strong when you make it, but it doesn't stick to your clothes. (Make a batch of soap and your whole house smells fresh and clean!)