Vilppu Drawing Manual, and taking it slowly. Due to music now taking the bulk of my hobby time, I'm limiting my drawing practice mainly to my lunch breaks. No digital or natural media practice.
I thought I'd understood spherical forms well enough, but after hitting the later chapters, I realized I didn't really, and went back to the earlier chapters and kept up with the practice.
I think I'll be keeping up with this for awhile, and really don't relish day-to-day posting up of spheres and cubes.