Try to reduce the amount of lines you use. Instead of happily scratching away to find the line you want, try to make a conscious decision from where to where you want the line to go, and what curvature you want it to have. "Shadow" the line by moving the pen over the pad a few times, before setting down the pen.
lines are too straight making the pose a bit stiff. try to use curvier lines even if they might feel uncomfortable, they will help