2d painting practice throughout the past year. Doing these helps me improve on understanding shape/form when modeling in a different way than just sculpting would. I do them when I'm tired after work or have a spare few minutes to put towards them, so some have been pushed farther than others.
I do not know who the owners of the original photos are that I used for reference for any of these, since I grab them quickly off random sites. I'm only using them for practice reference though and that's it.