Equal parts of Borax and Baking soda; Combine; Use 1-2 T per load
I used it for a while but I've never been a big fan of powdered detergent, so I just bought some cheap store-bought liquid dishwasher detergent and have been using that. Until it dawned on me that I could easily make a paste by adding water to the borax/baking soda powder. (yes, I know that should be common sense, but it seemed to have escaped me until recently lol).
So, to get homemade liquid dishwasher detergent, simply add water until you get the consistency you want! I use 2-3 T of the liquid per load.