From Mary Hunt's Everyday Cheapskate:
GREASE POLICE. Sometimes I find grease stains on my clothing, and I've found that dish soap is the most effective spot remover for greasy or oily stains. Since it is designed to cut the grease on pots and pans and still be gentle on your hands, dish soap makes the perfect product to use on tough oil stains in delicate clothing.
SALT SOLUTION. If you make your own laundry detergent and your whites are getting dingy, it is probably because you have hard water. Salt is the secret to softening your laundry water and brightening those whites. I use the cheapest salt I can find, without iodine. My water is extremely hard, so I use 1/2 cup of salt per load. I suggest starting with 1/4 cup. If your whites still come out dingy, add more salt next time.
SOFTENER SAVINGS. I stretch my liquid fabric softener until it screams. I pour about half of a cup of it in a spray bottle. Then, I fill the rest of the bottle with water. A few squirts into a dryer full of wet cloths does the job.