I made some progress today with identifying why I struggle with the brush pen. I draw with my wrist, rather than my arm and trying to do the latter results in nice line weight but comes at the cost of control. Practicing drawing with my arm should improve my coordination and hopefully allow me to have more than the almost minimal control/accuracy that I feel like I have currently. This drawing was done after doing two pages of practice lines, basic shapes, and toy drawings. The practice exercises definitely helped!