I've been making my own laundry detergent for over 2 years, and I love it. It's just equal parts of Arm & Hammer Washing Soda, grated Fels Naptha Soap, and Borax. You only need 1-2 tablespoons per load. There are no sudsing agents in this detergent, so it doesn't bubble up.
I also wash everything in cold water. IME, cold water actually works better at removing stains and odors.
And I use 1/2 cup of white vinegar in each load. White vinegar is a natural fabric softener, and it is an odor neutralizer. No, your clothes won't smell vinegary, in fact, they will lack any smell at all. I add the vinegar to the washer as it's filling up with water.
I use this detergent on everything from cloth diapers to my husband's work clothes to my frilly unmentionables. I will never use commercial detergent again. Nothing works as good, and this is super cheap to make. Grating the Fels Naptha is a little tedious, but you can pawn the task off onto your kids or husband. ;-) I make 3-4 months worth a time and keep it in a tupperware container.
[Arm & Hammer "Washing Soda" is NOT the same as baking soda. It comes in a bright yellow box and is sold with other "laundry aids" and stain removers. Fels Naptha is a bar laundry soap. I also use it as a stain pre-treater. It's amazing! Fels Naptha can be hard to find. I buy mine at a grocery store. I think Wal-Mart carries it, but Target does not. Borax is available anywhere, and is either going to also be by laundry aids or in the cleaning products aisle.]