You will need equal parts of borax and washing soda. Both of these items are found on the same aisle as your laundry detergent at most grocers. I put both items in a leftover lidded plastic container (mine is an old plastic container with a twist on lid). I screw on the lid and I shake. Done! I also found a small scooper from a different product that I use to dump the detergent into the dishwasher. I do not fill my dishwasher up to the brim with soap--I fill it halfway in both the prewash and main wash compartments. Here is the recipe I use when I make it--
2 Cups Borax
2 Cup Washing Soda
Combine; Shake; Store; Use as Needed
Happy washing and feel good that you are saving money and some creatures!