Well it just takes practice and dedication :) these typically take me 5+ hours to make, depending on size and detail. I have to say though, without Photopea, I wouldn’t be here. I strongly recommend the shape tools and warp function, and dodge/burn for shading. Also, if you’re making a lot of copies of a shape (like I did for the background stars), stay vigilant in rasterizing, merging, and saving, in case it crashes (that happened to me with “Greatest Warriors”)