One of the lesser understood features in Photoshop is the Gradient Map Adjustment Layer. This is unfortunate because it is really useful for creating richly colored, yet subtly toned image effects including mimicking traditional cross processed looks. In the following examples, I converted the original image to black and white using Lightroom’s Develop module, then opened the file into Photoshop and added a Gradient Map Adjustment Layer from the bottom of the Layers panel. Instead of using the default gradients, I clicked on the downward pointing triangle to the right of the gradient swatch in the Properties panel, and then clicked the gear icon and selected Photographic Toning. Although most of the presets appeared overly saturated when applied at 100%, that was easily solved by lowering the opacity of the Gradient Map Adjustment Layer. In the final example, I decided not to convert the image to black and white and instead use a Gradient Map Adjustment Layer to shift the colors in an RGB image.
Note: although you may achieve similar results for some effects using the Split Tone or Tone Curve panels in Lightroom’s Develop module or ACR, I prefer the level of control over both color and tone achieved using Photoshop’s gradients.