Hi @Diego Garcia Figueroa, these are nice studies! I attached a brief paint over for one of your images. My paint over doesn't tackle every principle about painting, I mostly focused on your values and lighting since that is what you mentioned. I just darkened your shadows a bit to give the image a stronger sense of light. I also added more indication of light and shadow in the fences, just so that there is a bit of a stronger feel of light consistency in your image. So in general, I think what you could work on is making the areas in your images where the light hits a bit lighter, and making your shadow areas a bit darker. The stand alone character/portrait paintings are feeling a bit flat, and it's because you're staying in that middle value range. I would say your Cthulu piece feels the strongest because you've hit such a high range of light lights, and dark darks, and this gives it a better sense of lighting. If you can incorporate that range into more of your images then I think your paintings will feel punchier. Of course, this won't apply to pieces with more ambient lighting scenarios, but we'll get there when we get there :). Hope this helps! I didn't go that far into depth with brush strokes, so let me know if you'd want me to tackle that as well!