This is a rather hilarious case study of a kitschy faux 80’s poster I found that actually demonstrates great photo shop skill and good step by step instruction on creating a good photo manipulation product. You can see the full process here.
He starts with a few basic stock images and selects and masks to get a pretty seamless scene. He then adds some more elements and uses adjustments to even out the coloration.
After this, he edits the colors and adds a few more elements to maximize the kitschy-ness.
Finally, he uses the reduce noise filter to smooth the overall look.