Photoshop

High contrast and slightly cross-processed look

1. Open your colour image and make the usual adjustments (levels/ curves/ removing blemishes...)
2. Duplicate your background layer
3. Convert this duplicated layer to black and white using whatever method you prefer
4. Select Image > Adjustments > Levels => increase the contrast by moving the black and white sliders inwards
5. Set the blending mode to overlay
6. Reduce the opacity until happy
7. Flatten image (Layer > Flatten Image)