Skin-dragging is an emerging type of haptic feedback that coveys both precise spatial and temporal tactile cues through the motion of a small pin dragged across the skin. While past research focused on building skin-dragging wearable devices with different form-factors, and testing their feasibility, it is still unclear what the user's perception of such haptic stimuli is, and how designers should generate dragging motionpatterns for informative feedback to be presented on a finger. In this work, we attempt to answer these questions. We therefore asked designers to create dragging motions using changes of speed, direction and length. We then tested the generated skin-dragging motions with a haptic smart-ring, classified them and extracted guidelines that can be used to convey rich and informative feedback on the fingers.