I applied to my roots and left on for 20 minutes, and then applied the rest of the mixture on down to the ends of my hair. I usually only apply color to my roots to color the grow out portion, but since I was concerned the color was a bit darker than my current color, I did the second step as well to avoid a reverse ombre look. I found the scent to be pleasant and on the mild side.
The instructions say to massage the mixtures around on your head just prior to rinsing, but I did not find that easy to do, as the cream is actually on the thicker side. On the positive end of the spectrum, that meant I also had no problems with the solution dripping.