You are capturing the human form very successfully. Consider doing more hands, feet and faces in preparation for adding details.
Wellm anakinana, your line economy is so yummily done in your job. I love how much solidity, boldness and power in your guts and polish of the figures. Way to go, anakinana, way to go!
My one, small suggestion is that though your lines are really getting enough of the slickness of the edges, or lines, but I'm not really getting enough of that raw earnestness in your quickest sketches. Would you kindly loosen up and free up your hand with 30 minutes of 29 second quick poses of the nude & clothed figures, all flipped vertically and horizontally in different ways, using our custom timer? (1800 seconds/29 seconds=62 poses and attitudes) The reason why is because, though your lines are gonna be a bit too lighter, but you'll be able to get your shoulder and elbow a lot more looser and freer that ever. Hope this helps, and good luck.