Maybe one thing you could try is being more deliberate with your strokes? They look a bit hairy, and that might inhibit how much they can flow. Also, I think drawing through will help with more flowy lines since there’ll be less stopping and starting. I recall Stan mentioning drawing-through being important. Also, the limbs look a little bubbly at times (a curve against the same curve), which I think adds to the stiffness. Playing around with asymmetrical patterns and rhythm may be good to experiment more with. Being aware of the areas tension can help. For example, on the left pose I can imagine quite a bit of tension on the toes of the foot to our right, while in the drawing it’s just kind of floating. I would personally try a sharp angle change on the toes to indicate all that weight.