I did another one today. I tried to pay more attention to the shapes, getting rid of some spots where my initial work felt unneeded or adding spots where help was needed deciphering the form. I also tried to keep my initial sketch and the "ink" edges much looser. My previous two images were drawn to a head-sized grid, but this one I tried to start from a more gestural approach and did a lot more relative measurements after that. I'm happy with most of it except for the right breast, which doesn't have a very clear shape. I wasn't really sure how to improve that.

These are great. Maybe thinking a little more about shape design might help it look a bit less mechanical like a Photoshop filter. I'd look at some classic comics inkers like Frank Frazetta, Al Williamson and Wally Wood, to name a few. Two spots in particular that stand out are the shadow on the bent kneecap in the first drawing, which could fit a little more smoothly with the nearby shadow, and the lower white area of the bent knee of the seated figure, which could stand to be opened just a bit more at the bend. This exercise has been on my mental list as well, and I hope I can do as well as you have when I get to it.