I've been focusing on "in every movement the entire body must be light and spirited". With a slight expansion in my hands as the Peng Jin is expressed at the end of the postures.
I'm also training a slight circling at the end of one posture or straight line and the beginning of the next. I've been using larger circles and refining them as I become more familiar with the feeling, until there is little to no perceivable movement on the outside but a definite feeling of circling on the inside.