To create the texture and shading of the whale's skin, start by lightly shading the entire body with a soft paintbrush. Then, use a blending tool to smooth out the shading and create a more even tone. Next, use darker shades of paint to add to the texture of the skin, such as the bumps and ridges. Finally, with a small brush, lighten the areas of the skin where the light would hit, creating highlights and shadows that give the whale a sense of depth and dimension.