Avoid any signs of human presence, such as buildings or trails, unnatural colors, unnatural patterns, unpleasant color, faded color, dull color, ugly colors, boring colors, bad anatomy, blurry colors, pixelated colors, trees, obscure colors, unnatural colors, harsh colors, clashing colors,  too much of one color, many colors, washed out colors, oversaturated colors, unnatural shadows, unrealistic lighting, unrealistic textures.