Brush pen practice

I'm trying to practice drawing with a brush pen to better get the hang of it. I love the look you can get out of brush pens in theory, but figuring out how to actually achieve that look is taking some experimentation. I spent last night catching up on Tivo and was playing around with brush pens the entire time. Let me know what you think!

Anyone have any suggestions for their favorite brand of brush pen? I have one made by Prismacolor and also a Tombow but would be curious to hear what others use as their weapon of choice...