FIlm Simulation 3: Colour - Cross Processing

Cross processing was a nice way to tweak the colours in the original captures. Basically, slide film was processed with the standard C-41 negative film process.
Overall contrast was increased, then yellow and blue shades might appear. In general, colour was distorted - but this effect was sought-after, indeed...

Cross-procesing curves applied to a landscape image.

To achieve this "feeling", red channel contrast is increased, burning the lights; green channel has also some slight contrast increase (a soft "S" curves adjustement), whereas the blue channel sees a drop in its effective contrast. See above image as example (red channel highlighted).
Compare the original image and the edited one - which one do you prefer?

Left: unedited version - Right cross processed version

Again, credit has to be given to Petteri Sulonen (check his great blog) and (in this case) and Mario Maggi, who took the time to create the curves for GIMP...
Specific curves adjustment may not result in "valid" images for specific pictures. You might try different themes...