Homemade DIAPER detergent:
1c washing soda (aka sodium carbonate, if you can't find it in the store, check the pool supply section in the hardware store, it's a ph booster I think, it should say 100% sodium carbonate in the ingredient list)
1c baking soda (omit if you have HARD water)
1/2c oxiclean (doesn't have to be baby type or even name brand, any will do)--double this if you have hard water.
Mix well. For a fl, use 2 TBS mixed into HOT water to dissolve it & pour into detergent dispenser. For a top loader, I would say to use 1/4 cup.
For REGULAR laundry detergent, add in a grated & ground bar of pure soap (Castile, Ivory, Zote, Fels Naptha). I grate in in the food processor and then used the cutting blade to pulverize it a bit. That's all. Soap is not good for diapes, since it builds up.
I've used the diaper recipe for about 2 months now and it's wonderful. It rinses out easily (great for my FL), is cheap, and cleans really really well.