Have clouds hanging from the lighting bars at different heights to create depth in the stage. Have to be careful about their interference with lights and can't hang them too low otherwise might interfere with set props such as the building or the airplane
tear paper towel in a random shape and using as a mask, using the stylus tool, a clean tip, and a light tapping motion, lightly sponge in sky with the shades of blue, peri, and pink ink. move the paper towel down the card several times, changing the angle of the paper towel each time. start with lightest colour first, and progress to the darker colours. you are making random cloud shapes, so be sure to leave plenty of white space in the sky.