Little by little, I'm doing it. This time I did a study too, of a picture of a picture I found on pinterest, aparently from a community from VK - https://vk.com/adyingdog - here's the pin on pinterest for a comparisson > https://br.pinterest.com/pin/642185228091473259/ . This study helped me with color choices and where to put detail, though I still struggle with them.
This time, on the drawing from head, the colors don't look as saturated, wich makes me happy, and also the contrasts are stronger. The shapes are better too, and I'm finally realizing why so many pros use the free select tool! Got a little messy with the cultist and the thing that's supposed to be a torch, so I'll try to do more lighting and shape studies next week. Overall, I think this week was a success! Pretty happy with the results.