Painter is a program that is blessed with a wide variety of really excellent, and extremely helpful instructors who specialize in a wide variety of skills. As such, if there is something that you want to do, you can almost always find somebody who can help you learn those skills listed here.
I spend alot of time working with many of these people to help make Painter the best program it can be. Because of that, I can attest that each of them is a master in their own respective skillset. My Painter training courses tend to be fairly generic, and more focused on the technical side of how the program is designed to work. This is done by design, so that you can gain a solid foundation, and then move on to whatever specific workflow/style/skills you want to learn... which many of these people are far better suited to help you with than I would be.
In the course of our discussions we often learn from each other, and help each other with issues we might be having. Recently, there was a question raised by Skip Allen regarding some brushes one of the visitors to his blog wanted to reproduce. I gave some assistance in the matter, and Skip has shared the information here. You can get both his and my brushes from that blog post (free), and see how he is using them to replicate the desired look in his video.
The only thing I might add to what Skip said is: Also try using the pause button (on properties bar) to pause the Real Watercolor diffusion, and complete the entire painting before allowing it to diffuse. This can yield a very nice soft effect.