Here's a web site that has a bunch of recipes:
10 Homemade Laundry Soap Detergent Recipes : TipNut.com
I am allergic to detergents (not all of them, but many). So when the brand I wasn't allergic to switched its formula (and I broke out in hives), I decided to make my own (also, money was tight, so it was a cost-saving measure). I make a variation of #4--I didn't have any containers to store liquid--I do now, but I like the powder one--I use Kirk's (I don't know if that is available in Canada--I buy it when I go to NY. I've been meaning to buy Fels, but keep forgetting when I'm in NY). I've used Ivory when I didn't have any Kirk's. I run the soap bar through the grater of my food processor, then I switch blades and use the chopping blade. At first, I would end up with clumps of soap on my clothes--making the bar soap finer solved that problem. I also add 1/2 c of baking soda to the mix (which is probably overkill since the washing soda is probably enough) and when I do the laundry, I will sometimes add tea tree oil to the water. I haven't bought laundry detergent for 6 months. I have always dumped about 1 cup of vinegar in the rinse cycle--but that was to get all the detergent residue out of the clothes AND to get the DROOL off my clothes.
I've been very happy with how well the homemade soap cleans. I am on my second box of borax and A&H washing soda.
I keep forgetting to buy liquid Castille soap when I'm in NY--have to go down again Monday. I have it on my list. I go through a lot of dish washing soap so wanted to try "homemade".