Not sure if everyone knows this trick, but thought I'd add it here just in case.
When pasting an isolated image onto a new background it can often look, well...photo-chopped, as they say.
Here's a trick to integrate the image into the new background.
1. Try and line up the light sources of the different layers, at least from the left or right, so flip the image or background as necessary.
2. Select the empty area around the image to be pasted and then expand it so that it overlays part of the image, like a border or an outline. You don't want it to be super thin or too chunky. The next step is to use the regular blur filter. Then reduce the selected area so the outline is thinner (by about half) and then use the blur more filter. Image resolution matters, so experiment to get the best results. We want the image to fade out into the background at the edges.
3. Use the color filters to get the tones of the image to match those of the background. This can be done on the foreground or background or both. They don't have to be exact, just match the coolness or warmth or whatever.
4. Once the layers have been composited into a single art image (before adding the titles and stuff), use the tone filter to adjust the colors once again. The idea here is that this filter will adjust the entire image which will better integrate the various images into one, so add blue or yellow or green or whatever. A little goes a long way. Once this is done, you can also dial up the saturation to amplify the effect.
5. The last part (if needed) is to introduce noise into the final image (single layer), but if you use this option, do it before step 4. Make sure the add noise filter is set to monochromatic. It doesn't take much. The idea is to make it look like a fine film grain. Again, since the filter is applied evenly to the entire image, it gives it a cohesive original image vibe, which is enhanced all the more by step 4 above.
Hope this helps.
