A spin-off of @Mrs. Sunshine's thread.

I have tried a couple of dry shampoos, but haven't been satisfied with the results. Maybe I'm not doing it properly, or not using the right kind? I have auburn hair with slightly darker roots, and the white powder is still rather obvious to me even after combing it out. I tend to get a greasy scalp, but I don't have time for a full-on showering, washing, drying, styling routine every day.

What kind do you use, and how do you apply it? Also, is there an ideal amount to use?