Simply add the Dawn dishwashing soap, Borax, and Washing Soda to the gallon container. Pour in 4 cups of HOT water, and shake to thoroughly dissolve all of the ingredients. Once everything looks thoroughly combined, fill the container the rest of the way with cold water.
When you do the laundry, just add 1/4 cup of this DIY homemade laundry detergent to the washing machine for a regular load. Use 1/3 cup for a large or extra dirty load.