Nice excercices, though I don't see the cylinders for the limbs in the overlays over the photos. Those cylinders and other 3D forms are really important, as they will be the bases for anatomy and volmes. I would also recommend to try not to deform the boxes ot match the figure, I see it seems to be trying to match the overall figure, but in the long run the boxes and cylinders are intended to emulate body parts, like the rib cage, pelvis and head, wich don't stretch that much.
At this phase it's better to keep their figure rigid (bending them a bit is perfectly fine), so in later excercices you can more easily put the more fine details like bones, muscles and features more easily.
