The illustration is pretty much done at this point. All that’s left to do is add some filters to give the image the right finishing effects. First I duplicate the layers, then merge them. This way I end up with one layer to which I can add effects later. I also duplicate that layer and add Gaussian Blur to it with a radius of about seven pixels (Filter>Blur> Gaussian Blur). I also change the layer mode to Lighten, so it creates a slight glow effect around the image, then erase the parts where I don’t want to have this effect. I also add Smart Sharpen (Filter> Sharpen> Smart Sharpen), noise (Filter> Noise>Add Noise) and move Green channel (Ctrl+4) slightly to the right (click Ctrl+2 to see the RGB channel).