looking to get better at capturing the form in a short time
I think one thing that might help is being more confident with your lines. Right now, your lines are pretty shakey and scribbley, which is making the poses harder to read. You can find a number of line-drawing excercises online; I use them to warm-up before I start drawing. I find they do help, over time. The other thing that helps is drawing consistently; my lines get scribbley when I go more than two days without drawing.