They are looking nice. I like the line set-up. Remember for gesture drawing to get the pose in as little lines as possible, so like for some of the drawings, most notably drawings 29 and 31 (if we count left to right) one line could be used for a whole side of the body. It's a test of confident line, which is why a short time frame is necessary. That said though, they look great and you show a good use of overlap to show dimension while keeping relative proportion.
If you want to go more dynamic in your poses, use artistic license and push the poses further (i.e. tilt a head farther than the model actually does it, draw an arm more angular than depicted, etc.). It makes for more dynamic poses.
Question: What were the times on these? 30 sec? 45?
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