smudge looks quite good, colors fit but the darkest smudge color could be the black from the render. try to make also layers above the render to work it in. it is good that you thought about lightning dots, but remember that they have to match with everything else. so take instead of white a lightly orange/yellow (near to white) color and place them around the render.
the fastest way to increase your outcome quality is to get a huge library full of fx stocks, c4ds, stocks and renders!
keep on your work, use every capability u got and i wait eagerly for your next outcome :hooray: