Wash the diapers on warm or hot and rinse thoroughly with cold water. You may need a second rinse.  Do not use Dreft. It will leave a coating on your diapers, making them less absorbent.

Do not use chlorine bleach or a detergent with chlorine bleach additive. Bleach will break down the fibers and drastically shorten the life of your diapers.

Do not use fabric softener. It will affect the absorbency of your diapers. Instead use ½ cup of vinegar in the rinse cycle if needed. Vinegar will soften your diapers.

Dry your diapers in the dryer on "normal" or line dry in the sun. The sun will help remove any stains, leaving your diapers bright and white. You may wish to throw sun-dried diapers in the dryer for a few minutes to soften them.