I do the same as Boogity, but I use Zote. I have tried regular bar soap, using the entire bar for 2 gallons and this time even using one bar to make just one gallon. Still just doesn't clean as well as Zote.
I use the homemade detergent to treat stains and it works well. When whites get to looking really dingy, I dissolve some Cascade auto dish detergent in some hot water, add that to the washing machine and set it on the soak cycle.
Last week I tried just 1/4 cup of Simple Green concentrate to wash clothes and I was surprised! Whites looked better, too.
I haven't had any problems with oily spots on clothes using homemade liquid detergent. Fabric softener is most likely the problem, IMO. I use vinegar now instead, love that stuff. I do miss the perfume smell..... but I love the homemade stuff!