Well, there's two ways. First one is by using soft brushes with low opacity, as they don't left any mark you can achieve some cool gradients. The second way is by using the blending brushes that comes with photoshop cs5/cs6 or even the finger tool Hope you finde it useful.
I opened Painter once, but there so many options and brushes in there that it's kind of overwhelming. After so many years using PS, I just feel confortable with the program as I know where everything is placed