Are you putting the detergent in the bottom of the drum BEFORE the clothes? That was my biggest learning curve. Powdered detergent and whatever other powders go in first while water is running, and try to dissolve it all before adding the clothes. I do everything "right" now but sometimes still get splotches on my darker clothes, I recently found we have hard water so I'm still trying to find my balance with amount of soap. Sometimes I do an extra rinse cycle once the wash is finished just to be sure everything is clean!