Hey there! You received some really good feedback on what you can do if you decide to paint using only one layer. I don't have much to add to that. What I would like to correct, though, are the values in your scene. Even if you're painting on a single layer, keep values and lighting in mind. The scene looks flat because the character doesn't stand out; there's no difference between the character's values and those of the rest of the scene. If the light source is behind the character, they should remain in shadow, with only the edges illuminated. This will make the character stand out immediately and create a stronger visual impact. :) Hope this helps!

